What is drill-down capability?
multiple choice
a. involves the aggregation of information and features simple roll-ups to complex groupings of interrelated information.
b. the ability to look at information from different perspectives.
c. finds the inputs necessary to achieve a goal, such as a desired level of output.
d. enables users to get details, and details of details, of information.

Enables the users to get details ,and details if details ,of information.

Explanation:

Drill - Down Capability is the capability that lets user to see more information by pointing and clicking on the specific element.For example - a report that displays literacy rate by state can allow the user to select a state and by clicking on it and user can see the literacy rate by county or city within that state.

Hence we conclude that option d is the correct answer that is  

answer inspecting packets in isolation from their context;