A is correct because RSTP alternate ports block traffic while receiving superior BPDUs from a neighboring switch. An alternate port is a backup port for a root port, which means it receives better BPDUs from another bridge than the current root port. However, an alternate port does not forward any traffic, as it is in a discarding state. It only listens to BPDUs and waits for the root port to fail. If the root port fails, the alternate port can immediately transition to a forwarding state and become the new root port.
C is correct because RSTP alternate ports provide an alternate higher cost path to the root bridge. An alternate port is selected based on the same criteria as the root port, which are the lowest bridge ID, the lowest path cost, the lowest sender port ID, and the lowest receiver port ID.
However, an alternate port receives a higher cost BPDU than the root port, otherwise it would be the root port itself. Therefore, an alternate port provides an alternate higher cost path to the root bridge than the root port.

The "Root ID" shows 4096.00:19:e2:55:36:1e. The first part of this ID, 4096, is the bridge priority of the root bridge.
The local bridge ID is shown as 32768.00:19:e2:55:1d:30, indicating that the local device has a default bridge priority of 32768, which is higher (and thus less preferred) than 4096.
Thus, the root bridge has a priority of 4096, and the local device is not the root bridge. The local device is participating in the RSTP topology and has identified another bridge as the root.

When an EBGP router advertises a route to a neighbor in a different AS, it appends its own AS number to the AS_PATH attribute. This helps other routers recognize the path the route has taken and prevents routing loops.
If an EBGP router receives a route advertisement that already contains its own AS number in the AS_PATH attribute, it will drop the route. This prevents the router from accepting a route that would create a routing loop.