Explanation:

- Let's outline the problem:

- The average weight of A, B, and C is 65 kg.

- The total weight of A, B, and C is 65 kg * 3 = 195 kg.

- The average weight of A and B is 62 kg.

- Therefore, the total weight of A and B is 62 kg * 2 = 124 kg.

- The average weight of B and C is 66 kg.

- Hence, the total weight of B and C is 66 kg * 2 = 132 kg.

- Now, let's find the weight of B:

- (A + B + C) = 195

- (A + B) = 124

- (B + C) = 132

- Using these equations:

- Subtract the equation for A + B from A + B + C:

- C = 195 - 124 = 71 kg

- Subtract the equation for B + C from A + B + C:

- A = 195 - 132 = 63 kg

- Let's use A + B = 124 to find B:

- B = 124 - A = 124 - 63 = 61 kg

- So, the weight of B is 61 kg.

- Correct Option: Option 4: 61 kg