Final answer:
The correct subnet mask with a CIDR of /27 is 255.255.255.224. The /27 notation means that the first 27 bits are used for the network portion, leaving the last 5 bits for host addresses.
Step-by-step explanation:
The correct answer to the question which subnet mask is represented with the CIDR of /27 is C. 255.255.255.224.
CIDR, or Classless Inter-Domain Routing, is a method for allocating IP addresses and routing. A /27 indicates that there are 27 bits used for the network portion. Converting this to a subnet mask, we segment the 32-bit IP address into four octets (as is standard in an IPv4 address). With 27 bits, the first three octets will be filled completely with a binary 1, which translates to 255 in decimal form. The last octet will have 3 bits set to binary 1 (128 + 64 + 32 = 224) and the remaining bits set to 0.
Therefore, option C aligns with the /27 CIDR notation indicating a subnet mask of 255.255.255.224.