Current generally accepted accounting principles require that the discount rate for calculating the present value of future postretirement health care benefits be based on:

a. The current rate of return on the reporting entity's investment portfolio.

b. The current average rate of return on the investment portfolio of other companies operating in the reporting entity's industry.

c. The current rate of return on plan assets held in similar health care plans.

d. The current rate of return on high-quality fixed-income investments.

Chooses the correct answer.