Correct option is D
Given,
121 : 12 ∷ 225 : 16 : : 441 : ?
(2nd – 1)2 =1st Number
121 : 12 → (12 -1)2 = 112 = 121
225 : 16 → (16 -1)2 = 152 = 225
441 : ? → (? -1)2 =441
(? -1)2 = (21)2
? -1 = 21
? = 22
Therefore, the correct option is (d).