Final answer:
The sentence in question is a compound-complex sentence as it includes two main clauses and one subordinate clause.
Therefore, option C is correct.
Step-by-step explanation:
The sentence 'While jumping spiders are known for their incredible leaping ability, they use their keen eyesight to hunt, and their colorful appearance often fascinates researchers.' is a compound-complex sentence. A compound-complex sentence contains two or more main clauses and one or more subordinate clauses. This particular sentence has two main clauses: 'they use their keen eyesight to hunt' and 'their colorful appearance often fascinates researchers', which are joined by the coordinating conjunction 'and'. It also has a subordinate clause: 'While jumping spiders are known for their incredible leaping ability', which cannot stand alone as a complete sentence.