B @ C 7 N R % 5 $ G 6 K M & 4 S # P U 5

Question: If numbers preceded by letters interchange positions and letters change to next in alphabet, which elements are fourth from left and eleventh from right?
Options:
A. F and 7, B. 6 and D, C. A and $, D. D and 6, E. None of these
Answer: "D"