Use the Following to Answer Questions

Multiple Choice

Use the following to answer questions:
Figure: ABC Company
-(Figure: ABC Company) Refer to the figure. The figure depicts the market for a water cleaner for home aquariums. After use it gets washed down drains and enters into streams where it improves the mineral content of the water and thus leads to better water quality and better fish growth. What is the efficient quantity in this market?

A) 1,600
B) 400
C) 2,000
D) 3,600