Answer:
a decrease in price and an increase in quantity.
Explanation:
Complementary good is a good wherein its use has an association with its complement . Goods are said to be complementary when the usage of good X requires more usage of good Y.
Example of complementary good is DVD player and a DVD disc. If there is an increase in price of DVD player, then there would be a decrease in price and quantity demanded for a DVD disc.
It therefore means that complementary goods are goods that are jointly consumed together.