Willis and Leslie orally agree to the sale of a parcel of land for $50,000: one-half payable now as a down payment; one-half payable in 30 days at the time of closing when the title will be transferred. The buyer, Willis, is to have possession immediately. Willis pays Leslie $25,000, takes possession of the land, and starts building a house. At the time of closing, Willis has made a substantial beginning on the house. However, Leslie refuses to transfer the title, claiming the oral contract is not enforceable. This contract is:
a. enforceable, because the statute of frauds does not apply to this interest in land.
b. unenforceable, because there is no writing signed by Leslie.
c. enforceable, because Willis has partially performed the oral contract and made improvements on the land.
d. unenforceable, because the parol evidence rule applies.