Answer:
The largest amount possible
Explanation:
I would say driver, as the other ones work from offices and desks
Each guide was helpful, but we forgot to thank them.
You should use the plural pronoun, because we don't know whether the guides were only males, or females, or whether there were both sexes.
"of insects" is an adjective phrase because it's a prepositional phrase that acts as an adjective. It modifies the word "group"; In other words, "of insects" is used to describe the word "group".
