Answer:
It is used to set the trusted state of an interface to allow classification of traffic for QoS based on the CoS value of the IP phone.
Explanation:
I would go with A) Tablet because that's basically a bigger phone and mobile cmp combined, its not D) because that's a synonym for a smartphone and not C) because paper and pencil is not like a smartphone, and not B) because that's like reading online books.
Raises 4th amendment issues when done without a warrant.