Select the pair from among the given options that is analogous to the given pair.

18 : 325

12 : 145

(NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g. 13 – Operations on 13 such as adding/subtracting/multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)​​

18 : 325

12 : 145

Logic:  (Number × Number) + 1

For 18 : 325,
18 × 18 = 324, then 324 + 1 = 325

12 × 12 = 144, then 144 + 1 = 145 

Now check the options:

Option A: 16 × 16 = 256, then 256 + 1 = 257 (Correct)

Option B: 8 × 8 = 64, then 64 + 1 = 65 (Incorrect)

Option C: 15 × 15 = 225, then 225 + 1 = 226 (Incorrect)

Option D: 9 × 9 = 81, then 81 + 1 = 82 (Incorrect)

Thus, correct option is (a)