59 Emma contracts to sell and Elton to buy a machine for NT$100,000, delivery of the machine and payment of the price to be made at a stated place on July 7. On July 7 both parties are present at that place. Elton gives Emma a check payable to Emma in the amount of NT$100,000 but Emma refuses to deliver the machine. Elton may sue Emma for her ______ .
(A) omission (B) non-performance (C) inaction (D) denial