Mark the letter A B C or D on your answer sheet to indicate the most suitable response to each of the following exchanges, Mark the letter A. B. C or D on your answer sheet to indicate the most suitable response to each of the following exchanges., Mark the letter A. B. C. or D on your answer sheet to indicate the most suitable response to each of the following exchanges, Mark the letter A. B. C or D on your answer sheet to indicate the most suitable response to each of the following exchanges