Dr. molina and his colleagues discovered that some man-made compounds were depleting the?
a. earth
b. rainforest
c. ozone layer
d. antarctica

The answer is C. Ozone layer

Mario Molina was a recipient, together with his mentor Frank Sherwood Rowland, of the 1995 Nobel Prize in Chemistry for his role in discovering that some man-made compounds, namely chlorofluorocarbon gases, were depleting the ozone layer.

d. new methods of assembly are introduced.

explanation:

this allows for the goods to be made on a larger scale. not faster because now it is shown to be made better, hence the greater productivity in the question. it is calling for something new to be introduced.