What wildcard mask would an administrator use in the OSPF network statement for the network 172.16.91.0 255.255.255.192?

To determine the correct wildcard mask for the OSPF network statement based on the provided subnet mask of 255.255.255.192, it's essential to first understand the process of calculating a wildcard mask.

A wildcard mask is derived from the subnet mask by subtracting each octet of the subnet mask from 255. In this case, the subnet mask of 255.255.255.192 can be broken down as follows:

• The first three octets remain the same, which are 255 for the first three octets.

• The last octet is 192. To find the wildcard mask, we subtract 192 from 255:

255 - 192 = 63.

This results in a wildcard mask of 0.0.0.63. The correct wildcard mask allows OSPF to match any IP address within this subnet (from 172.16.91.0 to 172.16.91.63), enabling proper routing of packets destined for any host within that address range.

The other choices represent different subnet ranges and wouldn't match the intended network, making them unsuitable for the OSPF configuration based on the network statement given.