Demand for Your Tie-Dyed T-Shirts Is Given by the Formula

Multiple Choice

Demand for your tie-dyed T-shirts is given by the formula where p is the price in dollars you can charge to sell q T-shirts per month. If you currently sell T-shirts for $10 each and you raise price by $2 each month, how fast will the demand drop?

A) 80 T-shirts per month
B) 20,000 T-shirts per month
C) 400 T-shirts per month
D) 10 T-shirts per month
E) 40 T-shirts per month