What are complementary goods? Explain how a change in the price of a complementary good can act as a demand shifter.

Substitutes are goods where you can consume one in place of the other.

Explanation:

The prices of complementary or substitute goods also shift the demand curve. When the price of a good that complements a good decreases, then the quantity demanded of one increases and the demand for the other increases.

answer; eliminate parking problems in cities, because a car took up only half as much space as a horse and buggy;

i am pretty sure it is d.