Explanation
Process mapping is a tool that helps to create a visual representation of a business process. It shows the steps, inputs, outputs, roles, and decisions involved in the process. Process mapping helps to understand the current state of the process, identify areas for improvement, and design the future state of the process. A BA should use process mapping to capture all aspects of the current state lead-to-customer business process, including the steps and inputs from both sales and marketing. References:
https://trailhead.salesforce.com/en/content/learn/modules/business-analysis-process-mapping/understand-process

Explanation
The missing component necessary to finish this user story is why because it describes the benefit or value that sales reps will get from having visibility into their pipeline revenue (such as forecasting sales performance or identifying opportunities). The who part of this user story is "sales reps" because it describes the user role or persona who will benefit from this feature or functionality. The what part of this user story is "visibility into sales rep' pipeline" because it describes the feature or functionality that sales reps want or need.

The business analyst should use a stakeholder analysis to gather additional perspective, feedback, and detail on the requirements from the NTO team. A stakeholder analysis is a technique to identify and understand the needs, expectations, interests, influence, and power of the stakeholders involved in a project. A stakeholder analysis can help the business analyst communicate effectively with the stakeholders, manage their expectations, address their concerns, involve them in decision making, and obtain their feedback and approval.
A business analysis plan is not a document to gather additional perspective, feedback, and detail on the requirements from the NTO team. A business analysis plan is a document that describes how the business analysis activities will be conducted, such as what techniques, tools, deliverables, roles, and responsibilities will be used. A business analysis plan can help the business analyst plan and manage their work, but it does not help them gather information from the stakeholders. A current state analysis is not a document to gather additional perspective, feedback, and detail on the requirements from the NTO team. A current state analysis is a technique to understand and document how the current situation or process works, what are its strengths and weaknesses, what are the problems or opportunities for improvement, and what are the root causes of the issues. A current state analysis can help the business analyst identify gaps and needs, but it does not help them gather information from the stakeholders. References:
https://trailhead.salesforce.com/en/content/learn/modules/business-analyst_skills-strategies/explore-techniques-i