Answer:
A: forms major percentage of amazon's overall revenue.
Step-by-step explanation:
Amazon's revenue stream is based on E-Commerce, advertisements and amazon web services. Amazon is a dominant e-commerce platform with more than 50% markets share in USA.in 2018 amazon made $7.2 billion in USA market through e-commerce business.
Amazon web services generated more than 50% income in 2018.In 2018 it generated income of $7.3 billion.