$4.\_\_\_\_\_\_\_\_.$ Which of the following is true with regard to an express offer under the common law?

A$.$ Express offers must be clear and definite as to all material terms.

B$.$ The person making an offer may also fix the terms upon which an offer can be accepted.

C$.$ An express offer may be rescinded at any time prior to a valid acceptance occurring.

D$.$ All of the above are true.

$5.\_\_\_\_\_\_\_\_.$ Which of the following is true of fraud and misrepresentation?

A$.$ It prevents a true meeting of the minds and frustrates mutual and voluntary assent.

B$.$ It is generally inconsistent with the duty of good$-$faith and fair dealing owed to all parties in privity of contract.

C$.$ Neither A nor B is true.

D$.$ Both A and B are true.