NAT Definitions

From the document you recfer to above:

Inside global address-A legitimate IP address assigned by the NIC or service provider that represents one or more

inside local IP addresses to the outside world.

Devices on the internet must have legitimate (global) IP addresses. So you are left with only B or C as possible answers.

If they are referring to devices on the corporate network that interface with the internet cloud (i.e Edge routers)

then indeed B is the correct answer.

While the sentence might not be the best way to phrase it, it is certainly better than some of the questions I have seen from CISCO - bad grammar and completely vague as to what they are trying to ask I think if CISCO paid more attention to how they specified their questions and instructions, more people would pass their exams.