Bulldog Logging Co

Bulldog Logging Co. agreed to clear 40 hectares of land for Palmer Construction Corp. who had paid in advance for this service. Later, Palmer realised that they only needed 35 hectares cleared and released Stapleton Logging from the contract after they had cleared just 35 hectares. What should take place in order for the original contract to be legally discharged?

A) The parties should place this waiver in writing and under seal.
B) Offer a tender of performance to Palmer Construction.
C) Do nothing, but be prepared to clear the 5 remaining hectares if requested.
D) The remaining 5 hectares will have to be cleared, otherwise a new contract will need to be negotiated.
E) Pay back an appropriate amount of the advanced payment thereby establishing the gratuitous promise.