Answer:
B) related-linked diversification.
Step-by-step explanation:
A related linked diversification strategy refers to expanding a company's product lines with products or services that are similar to the ones that it currently offers.
In this case, Amazon first sold books and selling a e-book reader follows a similar path. Since Amazon had spare cloud computing capacity, it decided to "lease it" to other businesses and is currently Amazon's star service that generates most of its cash.