Which of the following pairs of goods are considered complementary goods?

Complementary goods are products that are often used together, meaning that when the demand for one good increases, the demand for the other good also increases. A common example of complementary goods is coffee and sugar; many people like to add sugar to their coffee. If more people start drinking coffee, they will likely buy more sugar to go with it, showing how the two goods support each other's sales. This relationship happens because the use of one item enhances the experience of using the other. Understanding complementary goods helps businesses predict how changes in demand for one product can affect related products.