Reflecting telescopes are popular because they are more durable than a refracting telescopes.
There is a difference between these two types of telescopes, reflecting telescopes worked by reflecting light, they are also known as reflector and refracting telescopes worked by refracting light and they are also known as reflactor.
Reflecting telescopes also provides a good focus.
I'd go with electricity source. Good luck!!
I think that the oceanic water particles mainly move in circles greater in the oceans surface because of how big the waves can be and how wind and air impact the motion. The water particles move more on the surface because of the other factors that impact it such as people, wind, air, etc...
The answer i think would be D