Answer :
Answer:
D) substantial, but not complete, performance
Explanation:
Even though Moses breached his contract with Noelle, most part of the contract was performed. The most significant part of the contract was the apartment itself, not the air conditioning system. For a material breach to exist Moses should have failed to perform in a greater way, not just the air conditioning. Probably Noelle should get a discount on the price of the apartment so that she can get the air conditioning system installed.
The fact that Noelle stopped paying for the apartment just because of this is a little overreacting. For example, if I buy a used car and the previous owner forgets to give me the spare tire, I cannot stop paying because it may be worth money but proportionally it's a small amount.