Refer to the exhibit. A packet sourced from 10.10.10.1 is destined for 172.16.3.254. What is the subnet mask of the destination route?

0.0.0.0 is the subnet mask for a default route, indicating any destination not specifically routed, and is not a specific subnet mask for a particular destination IP address.

A subnet mask of 255.255.254.0 corresponds to a /23 CIDR prefix, which typically covers two contiguous Class B size network ranges, such as 172.16.2.0 through 172.16.3.255, encompassing the destination 172.16.3.254.

255.255.255.0 is a /24 subnet mask, which would only cover the 172.16.3.0 network; while 172.16.3.254 is within this range, 255.255.254.0 is a broader or more specific route implied by the correct answer.

255.255.255.255 is a /32 subnet mask, which represents a host-specific route matching only a single IP address, rather than a network route for a range of addresses.