Brick and Carmen are in an auto accident. Brick offers Carmen $2,000 if she promises not to pursue her potential legal claim against Brick. 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.The agreement between Brick and Carmen is___________.
a. a release.
b. a covenant not to sue.
c. promissory estoppel.
d. an illusory promise.
