'A' sends a registered insured parcel to 'B' by post but the post office does not deliver the parcel to 'B'. In the suit instituted by B against the post office, it is argued that since B is not a party to the contract between A and the post office. Therefore, it cannot sue for enforcement of the contract. Which of the following is the correct answer in such a situation?

• A. 'B' is not entitled to institute the suit
• B. 'B' can sue only on behalf of A
• C. 'B' can institute the suit because a implied trust has been created in his favor
• D. Only 'A' is entitled to institute the suit