The correct answer is: B. complementary
Complementary goods are goods that are used together. For example, a left shoe and a right shoe are complementary goods. You cannot use one without the other. Other examples of complementary goods include gasoline and cars, computers and software, and pens and paper.
Identical goods are goods that are exactly the same. For example, two identical apples are identical goods. Other examples of identical goods include two identical chairs, two identical shirts, and two identical cups.
Substitutes are goods that can be used in place of each other. For example, coffee and tea are substitutes. If you don’t want coffee, you can drink tea instead. Other examples of substitutes include hamburgers and hot dogs, pens and pencils, and apples and oranges.
None of these is not the correct answer.