What Is the Usual Effect of a Double Indemnity Clause

What is the usual effect of a double indemnity clause?

A) It provides that a single life insurance policy covers the lives of two people,typically a husband and wife.
B) It provides that the standard premiums purchase twice the amount of insurance coverage as they usually do.
C) It provides that the policy will pay twice the policy amount if death occurs within the first 10 years that the policy is in effect.
D) It provides that the policy will pay twice the policy amount if death is caused by an accident.