Kai Offers to Sell a Rare Book to Penny for $1,000

Kai offers to sell a rare book to Penny for $1,000. Penny wants to do more research first, but gives Kai $10 to hold the book for her for a week so she can buy it at the end of the week if her research shows the book is worth it. Kai takes Penny's $10 but dies the next day. Penny notifies Kai's widow that she wants to buy the book anyway. Does Penny have the right to buy the book for $1,000?

A) Yes, but only if Kai's surviving family members do not object.
B) Yes, but only if she sent her acceptance in the mail prior to Kai's death.
C) Yes, but only if the acceptance was received by Kai prior to his death.
D) Yes, as long as she acted to buy the book within a week of the original agreement.
E) No, because Paul's death invalidates their original agreement.