How does a switch treat a link aggregation?

How does a switch treat a link aggregation?
A . The switch treats the link aggregation as one logical link for spanning tree, but it learns MAC addresses separately on each individual interface within the aggregation.
B . The switch treats the link aggregation as one logical link. It assigns one spanning tree port role to the link aggregation, and it learns MAC addresses on the aggregation.
C . The switch treats the link aggregation as one logical link for MAC learning, but it assigns an individual spanning tree port role to each interface within the aggregation.
D . The switch treats each interface within the interface as a separate entity for MAC address learning; it also assigns an individual spanning tree port role to each interface.

Answer: B