The answer to your question is D.
Even though laws protect it
An adverb clause is a short sentence or a set of words that will modify a verb as would do an adverb -by explaining why, how, when or where.
In the given sentence, the adverb clause will modify the verb endangered, therefore the clause must refer to it. Options A, B and C, refer to the red panda, meanwhile option D is the only one referring to the mentioned verb.
The right answer is D.
