Which word or words from the paragraph best the reader understand the meaning of the underlined word?

bees swarm when the queen leaves the colony to make room for the new queen. several worker bees accompany the old queen. they fly in a group, with scout bees looking for a new place to live. the queen is not a strong flier, however, so the group surrounds and protects her when she stops to rest.

a.
looking for

b.
accompany

c.
fly in a group

d.
protects

the key word is swarm