Final answer:
All incidents of ownership held during the three-year period before death will cause the inclusion of life insurance proceeds in the gross estate.
Step-by-step explanation:
Included in the gross estate are all property that the decedent owned, controlled, or had an interest in at the time of death. Life insurance proceeds will be included in the gross estate if the decedent had any incidents of ownership over the policy during the three-year period before death. This means that if the decedent had the ability to change beneficiaries, access the cash value, or assign ownership of the policy, the life insurance proceeds will be included in the gross estate.