Robin and Bellman, both merchants, orally agree to a contract for the sale of $5000 of accessories. Bellman, the buyer, sends to Robin, the seller, a written confirmation of the sale, which is sufficient against Bellman under the statute of frauds and which Bellman signs. Robin does not sign. Robin fails to perform the contract and does not ship out the goods. Bellman sues. This contract is:
a. unenforceable, because Robin did not sign any contract.
b. unenforceable, because Bellman did not pay for the goods.
c. enforceable, because Bellman sent the written confirmation of the sale, thereby partially performing the contract.
d. enforceable even without Robin's signature because both parties are merchants.