Correct option is C
Given equation- 25 * 82 * 12 * 6 * 8 * 91
+, -, ÷, ×, = replace the * with these signs and apply the BODMAS rule-
25 + 82 - 12 ÷ 6 × 8 = 91
25 + 82 - 2 × 8 = 91
25 + 82 - 16 = 91
25 + 82 - 16 = 91
107 – 16 = 91
91 = 91