If at a price of $24, Octavia sells 36 home-grown orchids and at $30 she sells 24 home-grown orchids, the demand for her orchids is

The most important influence on a firm's demand for a factor of production is __________.

Fill in the blank(s) with the appropriate word(s).

In the above figure, the optimal level of pollution cleanup is

A) Q1.
B) Q2.
C) Q3.
D) Q4.