Explanation:

- We know \( A \) is 40% less than \( B \). So, \( A = B - 0.4B = 0.6B \).

- The sum of \( A \) and \( B \) is \( A + B = 0.6B + B = 1.6B \).

- \( C \) is 40% of the sum of \( A \) and \( B \), thus \( C = 0.4 \times 1.6B = 0.64B \).

- The difference between \( A \) and \( B \) is \( B - A = B - 0.6B = 0.4B \).

- Now, we find what percentage the difference is of \( C \):

$$

\left( \frac{0.4B}{0.64B} \right) \times 100 = 62.5\%

$$

- Option 1: 60.5%

- This is incorrect. The calculated percentage is higher.

- Option 2: 64%

- This is incorrect, as the calculated percentage is lower.

- Option 3: 62.5%

- This matches the calculation.

- Option 4: 60%

- This result is incorrect, being lower than the calculated percentage.