Correct Option: 4

Under the Transfer of Property Act, 1882, a vested interest is an interest in property that is certain and not dependent on any condition. This means that a vested interest cannot be defeated by the death of either the transferor or the transferee. The transferor's death does not defeat the vested interest, as the interest has already been granted and is not contingent on the transferor's life. Similarly, the transferee's death does not defeat the vested interest because it has already been vested in the transferee, and the rights are transferred. Therefore, neither the death of the transferor nor the transferee defeats the vested interest.