A server technician is configuring the IP address on a newly installed server. The documented configuration specifies using an IP address of 10.20.10.15 and a default gateway of 10.20.10.254. Which of the following subnet masks would be appropriate for this setup? 

Answer options:

A. 255.255.255.0
B. 255.255.255.128
C. 255.255.255.240
D. 255.255.255.254

D

Reference: https://www.calculator.net/ip-subnet-calculator.html?cclass=any&csubnet=30&cip=10.20.10.15&ctype=ipv4&printit=0&x=57&y=17