Which of the following statements concerning the characteristics of disability income insurance is correct?

a. During the elimination period, disability income benefits are paid.

b. When disability income benefits are being paid the insured still must continue making the policy premium payments.

c. The residual benefits clause preserves the purchasing power of the insureds disability income benefits.

d. In a cost of living rider, an adjustment is made for each year of benefits paid to the insured and is computed by using the same rate of change as, say, the Consumer Price Index.