The command ip nat pool name creates the pool that hosts can use to get onto the global internet. What makes option B correct is that the range 171.16.10.65 through 171.16.10.94 includes 30 hosts, but the mask has to match 30 hosts as well, and that mask is 255.255.255.224 . Option C is wrong because there is a lowercase t in the pool name. Pool name are case sensitive.
