The correct answer is C.

The 'Top-10 risks and risk outlook' is indeed the component of operational risk reporting that involves reporting a list of the top overall risks. This component is crucial as it provides a snapshot of the most significant risks that an organization faces at a given point in time. It is often derived from the risk register or risk inventory, which is a comprehensive list of all the risks identified by the organization. The 'Top-10 risks and risk outlook' not only lists these risks but also provides an outlook on how these risks might evolve in the future. This information is invaluable for decision-makers as it helps them prioritize their risk mitigation efforts and allocate resources effectively.

Choice A is incorrect. While a heatmap and risk register are components of operational risk reporting, they do not specifically report the top-10 overall risks. A heatmap visually represents the severity and likelihood of risks, while a risk register records details about identified risks.

Choice B is incorrect. Risk appetite metrics are used to measure an organization's willingness to take on risk, but they do not provide a list of the top-10 overall risks.

Choice D is incorrect. 'Incidents and near misses' refers to actual events or situations that almost led to an undesired outcome such as financial loss or legal issues. This component does not specifically provide a list of the top overall risks.