In the past, the idea behind mass production was to?

The choices can be found elsewhere and as follows:

A. produce goods of the highest possible quality.
B. give producers the maximum flexibility to respond to customer preferences.
C. make large quantities of a limited variety of products at very low cost.
D. give workers more control over their work environment. 

I believe the correct answer is option C. In the past, the idea behind mass production was to make large quantities of a limited variety of products at very low cost.