Yes, there is a mistake there and it still exists. I found it now also in Online Test Bank in Sybex. They even explain the correct answer themselves.

Which of the following are not globally based AWS services? (Choose two.) A. RDS B. Route 53 C. EC2 D. CloudFront

Explanation Relational Database Service (RDS) and EC2 both use resources that can exist in only one region. Route 53 and CloudFront are truly global services in that they’re not located in or restricted to any single AWS region.