Between 2008 and 2011, the number of US troops
b. increased significantly.
Step-by-step explanation:
This was in the time of Obama when the commitment of the nation had become to effectively end the war and in the process the nation had sent many troops to Afghanistan.
This is when the notion of the war on terror culminated and US gained strategic potion but was not able to break the land lock there.
The issue was not solved despite the highest deployment rates there.