What is the cost, in cents, of using a certain fax machine to send n pages of a report if the total cost for sending the first k pagers is r cents and the cost for sending each additional page is s cents? (Assume that n > k.)
(A) r + s (n - k) (B) r + s (n + k) (C) rs(n + k)
(D) kr + s(n - k) (E) kr + ns