Increasing research and development into new forms of renewable energy are most important because a) the price of gasoline is high. b) people like saving the planet. c) current forms of energy are being depleted. d) it is better to keep innovation progressing.

The correct answer is B) people like saving the planet.
Because of the usage of fossil oil and coal extensively in the last few hundred years the Earth and the environment are suffering very badly, this of course affects the humans, their health and life in total. It is obvious that if this trend continues we will make the planet unrecognizable and destroy big portion of it, which will make us suffer or die out as well, so people have been trying to develop renewable energy as much as possible for both the planet's and their own well being, but also are trying to make it as cheep as possible so that it is economically not damaging.

Why you put last one a? i think is b.

The zhou dynasty (1046-256 bce) was the longest-lasting of china's dynasties. it followed the shang dynasty (c. 1600-1046 bce) and it finished when the army of the state of qin captured the city of chengzhou in 256 bce.