Reference: the action of alluding or mentioning something; source; things that you have used for an assignment
“This means that Mikey waited for a very long time and got cold”
Tone is created through word choice, sentence construction/ word order, and by what the viewpoint is focusing on.
B. Solar power saves money for the user and makes the world a better place all around.
A is a personal opinion, C is not specific at al, D is factual, but it doesn't exactly make sense because though it helps the environment it doesn't really sustain our resources. Therefore B is the correct answer.