Under the traditional common-law mirror image rule, which statement best describes acceptance?

• A. The acceptance may be any form, even if it changes terms.
• B. Acceptance can add terms freely.
• C. Silence constitutes acceptance.
• D. The acceptance is effective only if it exactly matches the offer; otherwise it is a counteroffer.

Answer: (D)

Under the traditional common-law mirror image rule, acceptance must exactly reflect the terms of the offer. If the offeree adds, changes, or negotiates terms at all, the response isn’t an acceptance but a counteroffer that terminates the original offer. Silence does not count as acceptance, and the form or manner of acceptance doesn’t matter so long as the terms match precisely.

So the only time acceptance is effective is when it exactly matches the offer; otherwise, the response creates a new offer for the original offeror to accept or reject. For example, if someone offers to sell a car for $10,000 and the other party says, “I’ll buy it for $9,500 and with a different delivery date,” that’s a counteroffer, not acceptance.