Which provision allows changes in the policy only when expressed in writing?

The Entire Contract Clause is the correct answer because it states that the insurance policy, along with any attached riders, represents the complete and exclusive agreement between the insurer and the policyholder. This clause ensures that any changes to the policy must be documented in writing and agreed upon by both parties. This provision protects the integrity of the contract by preventing any alterations that were not formally recorded, thereby ensuring that all terms are clear and mutually accepted.

In contrast, the Change of Beneficiary Provision allows policyholders to modify who receives the death benefit, but this may not necessarily require that all changes be formally documented in writing. The Exclusions Clause lists specific situations or conditions that are not covered by the policy, but it does not pertain to changes in the policy itself. The Grace Period Provision grants policyholders a certain period to pay premiums after a due date without losing coverage, but it also does not involve changes to the policy terms that require written expression.