Soffers $$200$ to any employee who completes store inventory by $5$:$00p.m.$ that day. When employee J completes $75\%$ of the task, $5$ revokes the offer. J sues $5$ for breach of contract.

J will win because the parties had a unilateral contract, therefore $S$ could not revoke the offer once $J$ had substantially performed.

J will win because this was a bilateral contract, therefore $5$ could not revoke after J began taking inventory.

$S$ will win because there is no contract.

S will win because this is an illegal contract.