*The total number of devices = (150 + 10) users × 2 IPs per user = 320 devices
*Class C (D) supports a maximum of 254 hosts (2^8 - 2), which is too small.
*Class B (B) supports 65,534 hosts (2^16 - 2), making it the best choice.
*Why not the other options?
*Class A (C): Supports millions of addresses, which is overkill for 320 devices.
*Class D (A): Used for multicast, not for device addressing.