Sue Had a Beautiful Lakeside Cottage That Had Been in Her

Sue had a beautiful lakeside cottage that had been in her family for years.Times became a little tight,and Sue decided she had no choice but to sell the property.Sue agreed to sell the cottage property to her neighbour Bob for the sum of $250 000.Although Sue was ecstatic about the price early on,she soon changed her mind.There were too many memories for her to give the property up.Which of the following,by itself,would be the biggest barrier to Bob enforcing the agreement?

A) Unknown to Bob, at the time of the agreement Sue was mentally incapacitated.
B) The $250 000 price was not adequate, under the circumstances.
C) Bob and Sue had an agreement that their contract was not to be enforceable.
D) Although Sue had written a letter to Bob that discussed the essential terms of the agreement, Bob and Sue had not executed a written agreement.
E) No money had yet exchanged hands.