Suppose 1000 Units of a Good Are Sold at $10

Multiple Choice

Suppose 1000 units of a good are sold at $10 a unit. If its price increases to $20 and total revenue increases to $20,000 and increases by $1000 for every dollar increase in price after that, we know that

A) demand is perfectly elastic.
B) the demand curve is vertical.
C) the demand curve is downward sloping and the firm is on the inelastic portion of the demand curve.
D) the demand curve is a rectangular hyperbola.