Answer:
Complementary
Explanation:
A complementary product is a product whose use relates to the use of a similar or paired product.
Two products (A and B) complement each other if more of good A allows more good B to be used. In this instance, the electronic reader (Product A), requires the use of e-books and journals(Product B) to function.
The demand for one printers, for instance, produces demand for the other (ink cartridges). When the value of a product drops and people buy more of it, they typically buy more of the additional good as well, whether or not their price also falls.
