An increase in the price of socks is likely to decrease the demand for shoes and a decrease in the price of socks is likely to increase the demand for shoes. Socks and shoes are:

Complementary goods.

The correct answer is Option (3) → Complementary goods.

When two goods are used together, an increase in the price of one reduces the demand for the other, and a decrease in the price of one increases the demand for the other. Such goods are called complementary goods. In this case, socks and shoes are used together.

• If the price of socks increases, people buy fewer socks, and consequently, they also buy fewer shoes.

• If the price of socks decreases, people buy more socks, and hence, more shoes too.