What will be the port type of port 1?

In an RSTP network, the root and designated ports have been elected as shown in the exhibit

What will be the port type of port 1?

A.
backup port

B.
discarding port

C.
alternate port

D.
listening port

Explanation:
The two ports of switch B are connected to a shared LAN. One of them will be alternate port and other will be backup port. The ports that have better port priority become the alternate and the other port becomes backup. If port’s priorities are left at default values then the port that has lower number has better priority and becomes alternate. As the port in question has number “1” I assume that the other port can have number grater than 1. So the port 1 should have better priority and should become alternate port.