Which Is the Most Effective Statement in a Letter to a Customer

Multiple Choice

Which is the most effective statement in a letter to a customer about an order for which the customer has not yet paid?

A) We cannot ship your order until we receive your payment.
B) Your order will be canceled unless we receive your payment right away.
C) As soon as we receive your payment,we'll ship your order.
D) When are you going to submit payment?