What occurs when no ip classless is implemented on the router?

What occurs when no ip classless is implemented on the router?

• The router will only support classful IP addressing.
• The router will only support classful routing protocols.
• The router will use a default route, if present, when a matching route is not found in the routing table.
• The router will assume it has knowledge of all subnets in the network and will not search beyond child routes for a better match.

Exam with this question: CCNA Exploration 2: ERouting Chapter 8 Exam Answers