Answer: C) It is a dependent clause.
Explanation: an independent clause is a sentence that has complete meaning on its own (it has at least a subject, a verb and all the necessary complements), a dependent clause is the contrary, is a phrase that, in order to make sense, it needs to be with an independent clause. The given excerpt is a clear example of a dependent clause, because as we can see, it doesn't have complete sense, we can tell that it is missing something.
The last one...
there are not enough bicycles for the residents of the kilbarchan home for boys.
It is true that Uncle Tom's Cabin was translated into thirty-seven languages.