Executing the risk response plan in order to react to risk events throughout the project is called:

Contingency planning is the act of creating backup plans in advance, not the process of executing those plans when risk events occur.

Monitor and Control Risks is the process of implementing risk response plans, tracking identified risks, monitoring residual risks, identifying new risks, and evaluating risk process effectiveness throughout project execution. It ensures that risk responses are actually carried out and that newly emerging risks are handled appropriately.

Mitigation is a specific risk response strategy aimed at reducing the probability or impact of a threat, not the broader process of executing all risk responses.

Life cycle costing refers to evaluating total cost of ownership over a product's life span and is unrelated to risk response execution.