Harry needs help screening TV scripts and tells Joan that, if she "promises to stay off the sauce" (stay sober at work), he will make her his department assistant. Joan promises, but Harry decides to hire someone else. Can Joan sue Harry for breach of contract?

a.

Yes, a condition precedent triggered the duty to perform

b.

Yes, a condition concurrent triggered the duty to perform

c.

Yes, a condition subsequent affected performance

d.

No