Given conditions:

1. A is next to B but not next to C.
2. C is not sitting next to D.

Possible arrangement satisfying these conditions:

• If A is next to B but not C $\rightarrow$ $(A \ B \ C \ D)$, $(A \ B \ D \ C)$, $(D \ A \ B \ C)$, $(C \ D \ A \ B)$, $(B \ A \ D \ C)$, $(D \ C \ B \ A)$, $(C \ D \ B \ A)$, $(C \ B \ A \ D)$.

• Since C is not next to D, D must be placed at one end.

Valid arrangement: $(D \ A \ B \ C)$, $(C \ B \ A \ D)$

Therefore, A is occupying seats adjacent to D.