Select the option that is related to the third 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.

391 : 626 :: 426 : ? :: 173 : 408

661

391 : 626 :: 426 : ? :: 173 : 408

The logic followed here is :

Ist number +235 = IInd number

As

391 +235 = 626

And

173 + 235 = 408

Similarly

426 : ?

426 + 235 = 661