A is the registered proprietor of Torrens title land. A enters into a contract to sell the land to B. The contract contains a clause to the effect that B would honour an option to purchase the property granted for consideration to a long-term tenant. After B became registered, the tenant sought to exercise the option to purchase but B refused to sell the land claiming that he was not bound by the option granted by A. Will the tenant be able to enforce the option against B?