$113.$ Anish: "This is to confirm our telephone conversation of earlier today. $200$ lbs$.$ of T$-$bone at $$2\mathrm{.}89$ per pound."

Barb: "Yes, but that's $100$ pounds at $$2\mathrm{.}99."$

Anish: "Too late, we already reached agreement by phone."

Barb: "Too bad, it wasn't in writing."

Which of the following statements is true?

$$a$.$Barb is incorrect. The phone conversation was a contract.

$$b$.$Barb is correct. The agreement must be in writing to be enforceable.

$$c$.$Anish can enforce the agreement with the parol evidence rule.

$$d$.$Anish made a valid offer that must be accepted.