What subnet mask would a network administrator assign to a network address of 172.30.1.0 if it were possible to have up to 254 hosts?

255.255.0.0

255.255.255.0

255.255.254.0

255.255.248.0

ccna exploration 1 chapter 6 Exam Question And Answers 

What subnet mask would a network administrator assign to a network address of 172.30.1.0 if it were possible to have up to 254 hosts?