Explanation:

- Total initial calls are 24,000. Employee A handles 40% of them, equaling 9,600 calls. Employee B and C handle 30% each, equaling 7,200 calls each.

- For A, 80% of 9,600 initial calls become lead calls: \(0.8 \times 9600 = 7,680\).

- For A, 90% of 7,680 lead calls become final received calls: \(0.9 \times 7680 = 6,912\).

- Calculating calls not received by C: 30% of initial calls are \(7,200\) for C. 88% of these move to lead calls: \(0.88 \times 7200 = 6,336\).

- Difference noted: Calls not received by C are 4,464 less than A’s calls received: Calls not received = \(7200 - 6336 \times (y\%) = 4464\).

Rearrange to find \(y\):

$$

7200 - (6336 \times (y/100)) = 2464

$$

$$

6336 \times (y/100) = 4736

$$

$$

(y/100) = 4736 / 6336

$$

$$

y = (4736/6336) \times 100 = 74.7\approx 75

$$

Answer: Option:2, 75