The theme is the writer's view of or comment about the subject. The answer to your question is D. I hope this is the answer that you are looking for and it comes to your help.
The gene is responsible for the cat's hearing.
<span>It is important to determine weather the heat is coming from the bottom of the phone or from a different area because if you feel the heat is being emitted from the bottom of the phone, this is indicative of a battery overheating. If heat comes from other areas, it often means the phone itself is overheating.</span>