Which accountability (role = outdated term) in Scrum is responsible for explaining the items of the Product Backlog?

Which accountability (role = outdated term) in Scrum is responsible for explaining the items of the Product Backlog?
A . The Developer
B. The Requirements Engineer
C. The Project Manager
D. The Scrum Master
E. The Product Owner

Answer: E

Explanation:

It is one of the responsibilities of the Product Owner to explain the Product Backlog items. There are no Project Managers or Requirements Engineers.