The risk associated with an asset after controls are applied can be expressed as a function of the likelihood and impact, as it helps to measure and quantify the residual risk level and exposure. Residual risk is the risk that remains after the implementation of controls or risk treatments. Residual risk can be calculated by multiplying the likelihood and impact of a risk event, where likelihood is the probability or frequency of the risk event occurring, and impact is the consequence or severity of the risk event on the asset or objective. Residual risk can be expressed as:

ResidualRisk=Likelihood×Impact

Expressing the risk associated with an asset after controls are applied as a function of the likelihood and impact helps to provide the following benefits:

It enables a data-driven and evidence-based approach to risk assessment and reporting, rather than relying on subjective or qualitative judgments.

It facilitates a consistent and standardized way of measuring and communicating risk levels and exposure across the organization and to the external stakeholders.

It supports the alignment of risk management and control activities with the organizational strategy and objectives, and helps to evaluate the achievement of the desired outcomes.

It helps to identify and prioritize the areas for improvement and enhancement of the risk management and control processes, and guide the development and implementation of corrective or preventive actions.

It provides feedback and learning opportunities for the risk management and control processes, and helps to foster a culture of continuous improvement and innovation.

The other options are not the best ways to express the risk associated with an asset after controls are applied. A function of the cost and effectiveness of controls is a measure of the inputs or outputs of therisk management and control processes, but it does not indicate the risk level or exposure. The likelihood of a given threat is a component of the risk calculation, but it does not reflect the impact or consequence of the threat. The magnitude of an impact is a component of the risk calculation, but it does not reflect the likelihood or probability of the risk event.References=Risk Assessment and Analysis Methods: Qualitative and Quantitative,IT Risk Resources | ISACA,Residual Risk: Definition, Formula & Management - Video & Lesson …