Answer:
b. counterclaim
Step-by-step explanation:
Based on the information provided within the question it can be said that in this scenario Ava's claim is known as a counter claim. This term refers to a claim made in order to prove that a previous claim made against you is false. In this case Daniel made a claim against Ava, and Ava is rebutting that claim by stating that Daniel breached the contract, therefore making his claim void.