An aqueous solution 'A' turns phenolphthalein solution pink. On addition of an aqueous solution 'B' to 'A', the pink colour disappears. The following statement is true for solution 'A' and 'B'.

Options

A. A is strongly basic and B is a weak base.
B. A is strongly acidic and B is a weak acid.
C. A has pH greater than 7 and B has pH less than 7.
D. A has pH less than 7 and B has pH greater than 7

Answer

To solve the problem, we need to analyze the behavior of the solutions A and B in relation to phenolphthalein, a pH indicator.

### Step-by-Step Solution:

1. **Understanding Solution A**:
- The problem states that an aqueous solution A turns phenolphthalein pink.
- Phenolphthalein is a pH indicator that turns pink in basic (alkaline) solutions (pH > 7).
- Therefore, we can conclude that solution A is basic.

2. **Understanding Solution B**:
- When an aqueous solution B is added to A, the pink color disappears.
- This indicates that solution B must be acidic (pH < 7) because an acid neutralizes the base, resulting in a color change back to colorless.

3. **Analyzing the pH Values**:
- Since solution A is basic (pH > 7) and solution B is acidic (pH < 7), we can summarize:
- A has a pH greater than 7 (basic).
- B has a pH less than 7 (acidic).

4. **Conclusion**:
- The only statement that holds true for solutions A and B is that A has a pH greater than 7 and B has a pH less than 7. This aligns with the behavior of phenolphthalein and the neutralization reaction that occurs when B is added to A.

### Final Answer:
- A has a pH greater than 7 (basic), and B has a pH less than 7 (acidic).