Svana would like to purchase an individual insurance policy. Aftera discussion and thorough needs analysis, you determine that both a non-cancellable policy and a guaranteed renewable policy would meet Svana's needs. Eager to learn more, Svana asks you to explain the main differences between a non-cancellable policy and a guaranteed renewable policy. Which of the following statements is a CORRECT explanation that you can provide to Svana?

a) Guaranteed renewable policies typically provide coverage to age 60, whereas non-cancellable policies typically provide coverage to age 65.

b) Non-cancellable policy premiums can never be increased, whereas guaranteed renewable policy premiums can be increased.

c) For non-cancellable policies, any changes to the policy must be communicated to you in writing a minimum of 30 days in advance.

d) For a guaranteed renewable policy, only the policyholder has the right to modify any of the terms and conditions of the policy.