In a certain code language,
‘A + B’ means ‘A is the son of B’,
‘A – B’ means ‘A is the sister of B’,
‘A x B’ means ‘A is the wife of B’ and
‘A ÷ B’ means ‘A is the father of B.
How is Q related to D if ‘Q + E ÷ R – C x D’?

To find how Q is related to D in the expression ‘Q + E ÷ R – C x D’, we can decode the relationships step-by-step from right to left:

1. C x D: Since ‘A x B’ means ‘A is the wife of B’, C is the wife of D. This tells us that C is female and D is male (husband).
2. R - C: Since ‘A - B’ means ‘A is the sister of B’, R is the sister of C. Therefore, R and C are sisters.
3. E ÷ R: Since ‘A ÷ B’ means ‘A is the father of B’, E is the father of R. Since R and C are sisters, E must be the father of both R and C.
4. Q + E: Since ‘A + B’ means ‘A is the son of B’, Q is the son of E. Since E is the father of R, C, and Q, Q is the brother of R and C.

Now, we can connect Q to D:
C is the wife of D.
Q is the brother of C.
Therefore, Q is D's wife's brother (brother-in-law).

The correct option is Wife's brother.