The national response framework is:

a) activated only after a presidential disaster declaration.
b) in effect at all times and applicable to all types and sizes of incidents.
c) focused on natural disasters, whereas the protection and prevention frameworks focus on technological and human-caused incidents.
d) triggered following a declaration by the secretary of homeland security.

The correct answer to the following question will be "Option D".

Explanation:

This NFR system seems to be a reference to whether the country adjusts to crises and situations of all kinds. This is focused on adaptive, versatile, as well as capable of adapting principles defined in the Federal Incident Response Framework to coordinate key national goals and objectives.The NFR begins running after such an announcement by Domestic security Advisor. The armed area is then placed underneath the order of the US representative.

So that option D is the right answer.