Andrew's Demand for Fish Is: Q_A=12- 3P

Multiple Choice

Andrew's demand for fish is: Q_A=12- 3P. Betty's demand for fish is: Q_B=16- 4P and Cathy's demand for fish is: Q_C=20- 5P. Q is the number of pounds of fish and P is the price of fish per pound. If Andrew, Betty and Cathy are the only people living in their village, the slope of the village demand for fish is:

A) - 1/12.
B) - 1/4.
C) - 1/5.
D) - 1/3.