Bon, an agent for City Motors, Inc., e$-$mails Dale on May $1$ that the dealer will sell her a $2018$ Ford pick$-$up truck for $$25,000$ between May $1$ and July $1.$ Bon's offer to Dale is

irrevocable for the stated period.

irrevocable until Dale responds.

revocable at any time.

revocable on the payment of consideration to Dale.