What type of products are considered complementary based on the cross-elasticity coefficient?

The correct answer highlights products that exhibit a complementary relationship, where the consumption of one product increases the demand for another. The cross-elasticity of demand is a measure used to determine this relationship. For complementary goods, the cross-elasticity coefficient is negative, meaning that an increase in the price of one product leads to a decrease in the demand for the other.

In the case of chips and salsa, they are often consumed together; an increase in the price of chips could lead to a decrease in the demand for salsa, as they are typically enjoyed as pair. This strong association makes chips and salsa a clear example of complementary products, as they enhance the experience of consuming each other.

Other options, while potentially related, do not represent such a strong complementary relationship. Apples and pears are substitutes rather than complements, as they can replace each other in consumption. Cars and gasoline are also not purely complementary because while cars depend on gasoline, there are alternatives like electric cars, and the relationship isn't as unequivocal. Lastly, a phone and a telephone charger do share a complementary relationship, but it is more specific and less universally applicable than the chips and salsa pair, which is a widely understood and common combination. Thus, chips and salsa serve as the best example