What subnet mask would make the most efficient use of available addresses for a site with 22 IP phones, 20 PCs, 2 printers, and 2 scanners?

To determine the most efficient subnet mask for the given scenario, we first need to calculate the total number of devices that require IP addresses. The total is as follows:

• 22 IP phones

• 20 PCs

• 2 printers

• 2 scanners

This results in a total of 46 devices.

Now let's consider the subnet masks provided:

• A subnet mask of 255.255.255.192 has a subnet size of 64 addresses (2^6 = 64). Out of these, 2 addresses are reserved for the network and broadcast, leaving 62 usable addresses. This option provides more than enough addresses but is not the most efficient.

• A subnet mask of 255.255.255.0 is a Class C subnet that offers 256 addresses (2^8 = 256), with 254 usable addresses after subtracting the network and broadcast addresses. While it has a large number of addresses available, it is inefficient because it allocates a lot of unused address space for just 46 devices.

• A subnet mask of 255.255.255.224 yields a subnet size of 32 addresses (2^5 = 32). Out of these, 2 addresses are reserved,