What address can be used to summarize networks 172.16.1.0/24, 172.16.2.0/24, 172.16.3.0/24, and 172.16.4.0/24?

172.16.0.0/21
172.16.1.0/22
172.16.0.0 255.255.255.248
172.16.0.0 255.255.252.0.

ccna exploration 2 chapter 2 Exam Question And Answers 

What address can be used to summarize networks 172.16.1.0/24, 172.16.2.0/24, 172.16.3.0/24, and 172.16.4.0/24?