The important part for answering this question is: The non-profit organization is supported by grants and contributions from large defense contractors, including Raytheon, General Dynamics, DynCorp and others.
This justifies what answer for what question? Q & A:
Passage: The Institute for the Study of War (ISW) is a United States -- based think tank founded in 2007 by Kimberly Kagan. ISW describes itself as a non-partisan think tank providing research and analysis regarding issues of defense and foreign affairs. Others have described ISW as "a hawkish Washington" group favoring an "aggressive foreign policy". Though it had produced reports on the War in Afghanistan and the Iraq War, "focusing on military operations, enemy threats, and political trends in diverse conflict zones". The non-profit organization is supported by grants and contributions from large defense contractors, including Raytheon, General Dynamics, DynCorp and others. It is headquartered in Washington, D.C.

Question: Based on this passage, who funds the institute for the study of war?
large defense contractors , including Raytheon , General Dynamics , DynCorp and others