Contractor bids on a highway construction job, incorporating Guardrail Company's bid into its overall bid to the state. Contractor cannot accept Guardrail's offer until it gets the nod from the state. Contractor gets the nod from the state, but before it can accept Guardrail's offer, the latter revokes it. Usually a person can revoke an offer any time before it is accepted. Can Guardrail revoke its offer in this case?