The risk manager should choose to exploit opportunities, as this response aims to maximize the positive effects of opportunities, which can help recover the project's contingency reserve and profit margin.
Exploit is a positive risk response strategy that aims to ensure that the opportunity is realized 1. It involves eliminating the uncertainty associated with a particular upside risk and making it happen 2. For example, if there is an opportunity to reduce the project cost by using a cheaper supplier, the project manager can exploit it by signing a contract with the supplier and securing the savings. Exploit is the opposite of avoid, which is a negative risk response strategy that seeks to eliminate the threat or protect the project from its impact 2.
The other options are not appropriate for taking full advantage of opportunities. Mitigate is a negative risk response strategy that reduces the probability and/or impact of a threat 2. It is the opposite of enhance, which is a positive risk response strategy that increases the probability and/or impact of an opportunity 1. Accept is a risk response strategy that involves acknowledging the risk and not taking any action unless the risk occurs 2.
It can be applied to both threats and opportunities, but it does not actively pursue them. Transfer is a negative risk response strategy that shifts the impact of a threat to a third party, along with ownership of the response 2. It is the opposite of share, which is a positive risk response strategy that allocates ownership of an opportunity to a third party who is best able to capture it for the benefit of the project 1.
References: 1: How To Exploit and Enhance Project Opportunities - Project Risk Coach 2 2: A Guide to the Project Management Body of Knowledge (PMBOKGuide) - Sixth Edition, page 443-4451

According to the PMBOK Guide, one of the tools and techniques for the identify risks process is data gathering. Data gathering is the process of collecting information from various sources to identify potential risks that may affect the project objectives. Some of the data gathering techniques are brainstorming, interviews, checklists, assumption and constraint analysis, and document analysis1. To conduct a risk identification exercise using data gathering techniques, the risk manager should take the following actions:
* Arrange a team meeting, review the project's scope, and discuss dependency mapping. This action can help the risk manager to facilitate a brainstorming session with the project team and other subject matter experts, where they can generate a list of potential risks based on the project scope and the dependencies among the project activities. Dependency mapping is a technique that helps to identify the relationships and interdependencies among the project components, such as tasks, resources, deliverables, and stakeholders2. By reviewing the project scope and discussing the dependency mapping, the risk manager can ensure that the risk identification exercise covers all the relevant aspects of the project and does not miss any important risk sources.
* Ensure that all the relevant stakeholders participate. This action can help the risk manager to obtain different perspectives and insights from the stakeholders who have different roles, interests, and expectations in the project. Stakeholders are individuals or groups who can affect or be affected by the project outcomes. They may have valuable information, experience, or expertise that can help to identify potential risks that may not be obvious to the project team. By ensuring that all the relevant stakeholders participate in the risk identification exercise, the risk manager can increase the comprehensiveness and accuracy of the risk identification process and foster stakeholder engagement and buy-in1. References: PMBOK Guide, 6th edition, pages 397-399, 414-4151; Mastering the PMI Risk Management Professional (PMI-RMP) Exam, page 70

The project manager should have performed an analysis to ensure that the change request was valid and well- supported before submitting it to the sponsor. This would help in making a strong case for the change request and increase the chances of its approval.
The project manager should have performed an analysis to affirm the request is valid before submitting, as this would help to justify the need for the change and to demonstrate its impact on the project objectives, scope, schedule, cost, quality, and risk. The project manager should also have consulted with the project team, the subcontractor, and the risk owner to determine the best risk response strategy and to estimate the resources and time required for the change. By performing an analysis, the project manager could have increased the chances of getting the change request approved by the sponsor and avoided wasting time and effort on an invalid request. References: The Standard for Risk Management in Portfolios, Programs, and Projects, page
79; PMBOK Guide, 6th edition, page 115.

In situations where available time and funds are insufficient to address all identified risks, it's imperative to prioritize risks based on their potential impact on the project. Focusing on high-impact risks ensures that the most critical threats to project success are managed effectively within the constraints. This approach involves conducting a thorough risk assessment to categorize risks by their severity and likelihood, allowing the project team to allocate resources strategically. By concentrating on high-impact risks, the team can develop contingency plans that safeguard the project's primary objectives, even if lower-impact risks cannot be fully mitigated due to resource limitations.
PMI Risk Management Study Guide References:
The PMI-RMP Exam Preparation Study Guide emphasizes the importance of prioritizing risks, stating that
"project teams often face constraints in resources, making it essential to focus on risks that pose the greatest threat to project objectives."

In a complex program, it is crucial for team members to assume ownership of risks before these are delegated.
Encouraging the program team to assume risk ownership ensures that they are fully engaged and responsible for managing the risks assigned to them. This approach promotes accountability and helps ensure that risks are actively managed throughout the program's lifecycle.
PMI's guidelines on risk management emphasize the importance of assigning clear ownership of risks to ensure that they are effectively managed and that responsibilities are clearly understood by all team members.