|A) S||B) G|
|C) H||D) R|
2nd letter to the left of 17th letter from the right means (2 + 17 = ) 19th letter from the right = (26 - 19 + 1 =) 8th letter from the left end , i.e H. Thus, 8th letter falls into the second section of the reversed sequence. Now, the sequence FGHIJ is reversed and becomes JIHGF. Clearly, position of H remains unchanged. Hence the required letter is H.