Question

Vietnam proved to be a tough challenge for American soldiers because of what?

Answer 1

E. all of the above

is your answer

all of the factors on the top is true.
A) because there were lots of boot traps that finished off many American troops
B) these trails were used by the NVA, and were hard to locate
C) These inflicted heavy losses to the Allies, while having relatively less losses to their own side.
D) As mentioned before, because of unfamiliar terrain, the US couldn't put their military strength at it's strongest, as it was hard to map out and plan each attack accordingly every single time

hope this helps