Explanation:

- The present ages of A and B are in the ratio 9:10. Let's assume A's age is 9x and B's age is 10x.

- Five years from now, A's age will be (9x + 5) and B's age will be (10x + 5). The ratio of their ages will be 10:11.

- Set up the equation: (9x + 5)/(10x + 5) = 10/11.

- Solving this, you get x = 5. Therefore, A's current age = 9x = 45 years.

- C is two years elder than A, so C's current age is 47 years.

- Three years from now, C's age will be 47 + 3 = 50 years.

Thus, Option 5: 50 years is correct.