This eyewitness excerpt describes the fierceness of a battle in Vietnam.

"As the darkness was setting in, Captain Vargas organized and executed the withdrawal of his Company from the landing zone by foot ... Over 1,000 rounds of incoming [artillery and mortar fire] fell on the men that afternoon and evening." - Lt. Col. William Wiese, 1968

What does this excerpt tell you about the nature of the fighting in Vietnam?
a) The Communist forces lacked heavy weapons like artillery.
b) American troops withdrew easily by by helicopter.
c) US troops had to move and fight the enemy on ground
d) Fighting stopped during the night to each side could recover