Final answer:
The buyer's guide must be provided to the applicant of a life insurance policy with an unconditional refund of less than 12 days at the time of policy delivery.
Step-by-step explanation:
The buyer's guide must be provided to the applicant of a life insurance policy with an unconditional refund of less than 12 days at the time of policy delivery. This is the only option mentioned that aligns with the requirement described in the question. The buyer's guide is an important document that provides essential information about the policy to the applicant, including details about coverage, premiums, and any limitations or exclusions.