Key performance indicators (KPIs) are the most effective for communicating forward-looking trends within security reporting. KPIs are metrics used to measure progress towards a specific goal or objective, and can provide insight into the current state of security and any potential issues or risks that may arise in the future. Key control indicators (KCIs), key risk indicators (KRIs), and key goal indicators (KGIs) are all important for measuring security performance and identifying areas for improvement, but KPIs are the most effective for communicating forward-looking trends.
Reference that support this statement include:
"Key Performance Indicators (KPIs) for IT Security" by ISACA. This resource states that KPIs "can be used to measure the performance of security controls and identify trends in security risks."
"Measuring and Managing Information Risk: A FAIR Approach" by The Open Group. This guide states that "KPIs are used to track progress over time and to identify areas where improvements may be needed."
"Key Performance Indicators (KPIs) for Cyber Security" by SANS Institute. This resource states that "KPIs can be used to identify potential risks and measure the effectiveness of security controls.

According to the Certified Information Security Manager (CISM) Study Manual, a mature information security culture is one in which staff members regularly consider risk in their decisions. This means that they are aware of the risks associated with their actions and take preventative steps to reduce the likelihood of negative outcomes. Other indicators of a mature information security culture include mandatory information security training for all staff, documented and communicated information security policies, and regular interaction between the CISO and the board.
Maintaining an information security governance framework enables an organization to identify, assess, and manage its information security risks. By establishing policies, procedures, and controls that are aligned with the organization's objectives and risk tolerance, an information security governance framework helps ensure that information security risks are managed to an acceptable level.
According to the Certified Information Security Manager (CISM) Study Manual, "Information security governance provides a framework for managing and controlling information security practices and technologies at an enterprise level. Its primary objective is to manage and reduce risk through a process of identification, assessment, and management of those risks." While the other options listed (prioritizing resources, communicating guidelines, and remaining compliant with regulations) are also important benefits of maintaining an information security governance framework, they are all secondary to the primary benefit of managing business risks to an acceptable level.
Reference:
Certified Information Security Manager (CISM) Study Manual, 15th Edition, Pages 60-63.

The most important element in achieving executive commitment to an information security governance program is to align the program with the identified business drivers of the organization. Business drivers are the factors that influence the strategic objectives, goals, and priorities of the organization. They reflect the needs and expectations of the stakeholders, customers, regulators, and other parties that are relevant to the organization's mission and vision. By aligning the information security governance program with the business drivers, the executive can demonstrate the value and benefits of information security to the organization's performance, reputation, and competitiveness. The other options are not the most important element, although they may be part of an information security governance program. A defined security framework is a set of standards, guidelines, and best practices that provide a structure and direction for implementing information security. A process improvement model is a methodology that helps to identify, analyze, and improve the processes related to information security. Established security strategies are the plans and actions that define how information security supports and enables the business objectives and goals. These elements are important for developing and executing an information security governance program, but they do not necessarily ensure executive commitment unless they are aligned with the business drivers