B. It delivers nutrients and oxygen.
Answer:
Your answer is D). Like most cold-blooded animals, geckos' bodies are unable to maintain a homeostatic body temperature on their own, therefore they must bask in the sun in order to increase their body heat, and hide in the shade when it's too hot.
Light is a form of EM radiation.
EM radiation has no mass (it's just energy packets called photons).
EM radiation can travel through a vacuum. (The speed of light in a vacuum is called c and is around 300,000 m/s).
Hope this helps!