Fact Pattern 10-4 (Questions 29-30 Apply)

Fact Pattern 10-4 (Questions 29-30 apply)
Dex and Carmen are in an auto accident.Dex offers Carmen $2,000 if she promises not to pursue her potential legal claim against Dex.Carmen agrees.Later,Carmen discovers that it will cost $1,500 to repair her car and $4,000 to cover the medical expenses for a latent injury.
-Refer to Fact Pattern 10-4.The agreement between Dex and Carmen is

A) a covenant not to sue.
B) an accord and satisfaction.
C) a release.
D) promissory estoppel.