Which of the following statements is correct?

a. A per capita distribution is the most common method of distributing proceeds to beneficiaries.

b. If the policy owner designates a per stirpes distribution of the proceeds, the designation becomes irrevocable once a beneficiary predeceases the policy owner.

c. A per stirpes distribution means that a beneficiary's share of a policy's proceeds will be passed down to his or her living child or children if the named beneficiary predeceases the insured.

d. A per capita distribution ensures that an insured's surviving family will share in the insurance proceeds.