Annias offers to sell her house to Tobias in consideration of $220,000. Tobias says he will pay $219,000. What is the status of this exchange of promises at this time?

Multiple Choice

• This is a unilateral contract that can only be accepted by performance.
• This is an offer and a counteroffer that terminates Tobias's power of acceptance of the original offer.
• This is an offer and a counteroffer that does not violate the mirror image rule of contracts, Tobias still has the power to accept the original offer.
• This is a bilateral, valid contract because the difference of less than one-half of one percent is trivial and not material.