If 'P % Q' means 'P is the father of Q'; 'P ! Q' means 'P is the sister of Q' and 'P * Q' means 'P is the daughter of Q', which of the following shows that 'I is the sister of K's husband'?

We need to find an expression where I is the sister of K's husband. This implies I must be female, and K's husband (let's say G) must be I's brother.
* Options A and D start with 'I % G', meaning 'I is the father of G' (making I male), so we can eliminate them immediately.

Let's evaluate *Option B: I ! G % H K

1. $I!G$ ** $\to$ I is the sister of G (I is female).
2. **$G\%H$ ** $\to$ G is the father of H (G is male).
3. **$H\ast K$ ** $\to$ H is the daughter of K (K is female/mother of H).

From points 2 and 3, since G is the father of H and K is the mother of H, G is the husband of K.
From point 1, I is the sister of G.
Thus, I is the sister of K's husband (G). This matches our target relationship perfectly.