McKenzie tells Daniel that if he performs his legendary Slick Rick$-$inspired $$Torts Rap$$ in class a second time that she would give him a perfect rating on RateMyProfessors.com at the end of the final exam. Following the conclusion of the last lecture, Daniel puts on a show, complete with lights, fireworks, a DJ$,$ backup dancers and t$-$shirt cannons for his class while performing the rap alongside special guest Ice Cube, who agreed to fly in from his busy touring schedule just for the performance. After seeing the entire performance, McKenzie thinks that the rap was $$good$,$ not great$,$ and because she did not end up with a t$-$shirt, decides not to post a rating online after all. If Daniel sues McKenzie for breach of contract since he fully performed, what is McKenzie$$s best counterargument?

Group of answer choices

McKenzie$$s promise fails for lack of mutual assent, as her offer of a $$perfect rating$$ is not considered a definite term.

McKenzie$$s promise fails for lack of consideration under the illusory promise exception, as she could change the terms at any time.

McKenzie$$s promise fails for lack of consideration under the past consideration exception, as Daniel already completed the Torts Rap.

McKenzie$$s promise fails for lack of consideration under the preexisting duty exception, as Daniel was already required to perform the Torts Rap under his teaching contract with SBCC$.$