What types of routes can a router learn?

A router can learn both static and dynamic routes, as well as connected routes if the interface is "up." Static routes are manually configured by a network administrator and are not subject to changes unless modified by the administrator. Dynamic routes, on the other hand, are learned automatically through routing protocols, allowing the router to adapt to network changes.

Connected routes are those that are directly attached to a router's interface that is in an "up" state. This means that a router will automatically include routes for any directly connected networks as long as the relevant interface is operational. Thus, the correct answer encompasses these three types of routes, highlighting the ability of a router to manage a variety of routing information based on its configuration and the state of its interfaces.