Passage: In order to exploit the victory in the Battle for Henderson Field, Vandegrift sent six Marine battalions, later joined by one U.S. Army battalion, on an offensive west of the Matanikau. The operation was commanded by Merritt Edson and its goal was to capture Kokumbona, headquarters of the 17th Army, west of Point Cruz. Defending the Point Cruz area were Japanese army troops from the 4th Infantry Regiment commanded by Nomasu Nakaguma. The 4th Infantry was severely understrength because of battle damage, tropical disease, and malnutrition.

Question: How many marine battalions did Vandergrift dispatch?
six