Read the following announcement and mark the letter A, B, C, or D on your answer sheet to indicate the correct option that best fits each of the numbered blanks from 13 to 16.

Dear Mr Peterson,
I would like (13) ____ a change in our delivery service policy to your attention. Until now, we have always provided free delivery for (14) ____ order. However, (15) ____ increasing fuel prices, we regret that this service will now only be available for orders of (16) ____ £100. I want to take this opportunity to thank you for your most valued custom.