You must write a sales letter to prospective customers. What should you do in the opening of your sales letter? ( )

A、Offer something valuable, promise a benefit to the reader, or use some other technique to gain your reader's attention.
B、Convince your reader of the superiority of the product or service being sol
D、
C、Motivate your reader to take action.
D、Promise an incentive for responding by a specific date.