Correct option is D
Given:
91, 102, 119, 142, 171, ?
Logic: The series follows a pattern of adding numbers that increase by 6.
91 + 11 = 102
102 + 17 = 119
119 + 23 = 142
142 + 29 = 171
Next difference = 29 + 6 = 35
171 + 35 = 206
Thus, correct option is (d).