Select the option that is related to the fourth number in the same way as the first number is related to the second number and the fifth number is related to the sixth number.

12 : 146 :: ? : 443 :: 16 : 258

21

12 : 146 :: ? : 443 :: 16 : 258

The logic followed here is :

Second number - 2 = 146 - 2 = 144 and square root of 144 is 12

and

258 - 2 = 256 and square root of 256 is  16

similarly

443 - 2 = 441 and square root of 441 is 21