Question

When the price of good A rises from $180 to $220, the quantity of good A demanded decreases from 250 to 150 units a day, and the quantity of good C demanded increases from 75 to 125 units a day.

From this information, we can determine that _______.

A. the cross elasticity of demand is positive, so the two goods are substitutes

B. the goods are complements because as the price of good A changes so does the quantity demanded of good C

C. good C is a normal good because as the price of good A rises, people switch to good C

D. the cross elasticity of demand is less than 1, so the two goods are substitutes