Select the pair from among the given options that is analogous to the given pair.
3 : 31
2 : 12
(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.) ​​

3 : 31
2 : 12

Logic: First number cube + 4.

For 3 : 31:

3³ = 27, 27 + 4 = 31 (which matches)

For 2 : 12:

2³ = 8, 8 + 4 = 12 (which matches)

Now, applying the same pattern to the options:

Option A: 6 : 220

6³ = 216, 216 + 4 = 220 

Option B: 4 : 65

4³ = 64, 64 + 4 = 68 (doesn't match 65)

Option C: 5 : 128

5³ = 125, 125 + 4 = 129 (doesn't match 128)

Option D: 8 : 35

8³ = 512, 512 + 4 = 516 (doesn't match 35)

Thus, correct option is (a).