# If in each of the following groups of numbers, last two digits are interchanged and after that they are arranged in descending order, then what will be the first digit of the middle group? 257, 491, 623, 846, 738

If in each of the following groups of numbers, last two digits are interchanged and after that they are arranged in descending order, then what will be the first digit of the middle group? 257, 491, 623, 846, 738.

Options: (A) 7 (B) 4 (C) 8 (D) 6