55.
The answer is: B
Explanation
Let's analyze the given conditions carefully:
- Four children: A, B, C, and D are sitting in a row.
- A is sitting next to B but not next to C.
- C is not sitting next to D.
Step-by-step Placement:
- Since A is next to B but not next to C, A and C cannot be adjacent.
- C is not next to D, meaning D must be placed in a way that avoids C.
Now, let's arrange them:
Possible arrangement:
- Since A must be adjacent to B and not C, let’s consider a possible order:
- Here, A is next to B.
- A is not next to C (which satisfies the first condition).
- C is not next to D (which satisfies the second condition).
C B A D
Now, looking at who is adjacent to D:
- In C B A D, A is the only one adjacent to D.
Thus, the correct answer is:
B: A