The correct answer is Option 2.One may use the prefix-length instead of the netmask command.The prefix length is another way of expressing the subnet mask. The prefix length is the number of bits set to 1 in the subnet mask. It is written in œslash notation, a œ/ followed by the number of bits set to 1. For example, if the subnet mask is 255.255.255.0, there are 24 bits set to 1 in the binary version of the subnet mask, so the prefix length is 24 bits or /24. The prefix and the subnet mask are different ways of representing the same thing - the network portion of an address.??Hence the correct answer is, prefix-length.