Which type of life insurance beneficiary requires his/her consent when a change of beneficiary is attempted?

An irrevocable beneficiary is the correct answer because this type of beneficiary has a legal right to the policy benefits and must provide consent for any changes to be made to the beneficiary designation. Once the policyholder designates an irrevocable beneficiary, that beneficiary's rights are protected, and the policyholder cannot change the beneficiary designation without obtaining the irrevocable beneficiary’s approval.

In contrast, a revocable beneficiary can be changed at any time by the policyholder without needing the beneficiary's consent. This reflects greater flexibility for the policyholder regarding who will ultimately receive the policy benefits. Other types of beneficiaries, such as contingent and primary beneficiaries, typically do not have the same level of protection and rights as an irrevocable beneficiary, meaning that changes can be made without their consent.