Concept: The insured must have a financial stake in the subject matter of insurance.Explanation:Insurable interest means the insured will suffer a financial loss if the insured item is damaged, destroyed, or lost.Without this interest, the insurance contract becomes invalid because the insured has nothing to lose.The principle ensures that insurance is not used for gambling or making a profit from a loss.Only a person who can suffer financial loss can take out a valid insurance policy.Answer: C. insurable interest