Drag and drop the restrictive participial phrase into the box to complete the sentence.
the campers were safer during pool time.
a) having taken lessons
b), having taken lessons
c) , having taken lessons,
d) having taken lessons,

It's definitely C.

Explanation:

Reformulate and break the sentence like this first,

It sounds better !

2. Second phrase: the "[were safer during the pool time.]" is added to complete the first sentence.

When we join to sentences to form one, we usually use conjunctions/connectives and punctuations as well !

So add the ',' to join these two sentences.

The final anwer would be: "The campers, having taken lessons, were safer during the pool time."

I hope that this was helpful enough ! :)

what novel are you talking about?