GMAT Sentence Correction (SC) | Re: The ‘lazy’ bees that account for almost 80 percent of the bee hive

The ‘lazy’ beesthat account for almost 80 percent of the bee hive population usually contribute little to the activities of the hive, but working as hard as the remaining 20 percent, the foraging bees, if the latter disappear from the hive.

A)that account for almost 80 percent of the bee hive population usually contribute little to the activities of thehive, but working
B)account for almost 80 percent of the bee hive population usually contribute little to the activities of the hive;