QL 2 is related to SG 16 in a certain way. In the same way, EI 6 is related to GD 20. To which of the following is PN 8 related, following the same logic?

The correct option is RI 22.

Let us analyze the relationship between the terms in each pair to find the underlying logic. Each term consists of two letters followed by a number.

Let's map each letter to its position in the standard English alphabet:
A = 1, B = 2, C = 3, D = 4, E = 5, F = 6, G = 7, H = 8, I = 9, J = 10, K = 11, L = 12, M = 13, N = 14, O = 15, P = 16, Q = 17, R = 18, S = 19, T = 20, U = 21, V = 22, W = 23, X = 24, Y = 25, Z = 26.

First Pair: QL 2 and SG 16
Let's look at the first letter of each term: Q and S.
Alphabet position of Q = 17
Alphabet position of S = 19
Difference: 19 - 17 = +2
Let's look at the second letter of each term: L and G.
Alphabet position of L = 12
Alphabet position of G = 7
Difference: 7 - 12 = -5
Let's look at the numbers: 2 and 16.
Notice that if we multiply the alphabet positions of the letters of the first term (Q = 17, L = 12) and check their sum or product, we can look for a relation. Alternatively, let's look at the relation between the numbers directly:
First number = 2
Second number = 16
Notice that: $2\times 8=16$, or perhaps the numbers are related to the letters.

Second Pair: EI 6 and GD 20
Let's verify the letter transitions:
First letter: E to G
Alphabet position of E = 5
Alphabet position of G = 7
Difference: 7 - 5 = +2 (Matches the +2 logic)
Second letter: I to D
Alphabet position of I = 9
Alphabet position of D = 4
Difference: 4 - 9 = -5 (Matches the -5 logic)
Let's look at the numbers: 6 and 20.
Let's find a pattern connecting the numbers: 2 to 16, and 6 to 20.
In both cases, the difference between the second number and the first number is:
For the first pair: 16 - 2 = 14
For the second pair: 20 - 6 = 14
Thus, the second number is obtained by adding 14 to the first number.

Applying the logic to PN 8:
First letter of the related term:
Alphabet position of P = 16
Applying the +2 shift: 16 + 2 = 18
The letter at position 18 is R.
Second letter of the related term:
Alphabet position of N = 14
Applying the -5 shift: 14 - 5 = 9
The letter at position 9 is I.
Number of the related term:
First number = 8
Applying the +14 shift: 8 + 14 = 22
The resulting number is 22.

Combining these parts, the term related to PN 8 is RI 22.