In which way did the goals of the
United States in the Vietnam War
differ from the goals of the United
States during World War 11?

A. The United States waged
a defensive war to
protect an ally

B. The United States was
fighting to acquire
territory

C. The United States was
trying to expand the
territory of its ally

D. The United States
supported the survival of
a colonial power.

The goals of US differed as:

A. The United States waged  a defensive war to  protect an ally

Explanation:

The US had entered both the wars on very separate terms and separate reasons.

One of the biggest reasons of entering the first world war was to ally the powers of Britain and France for goodwill and largely business concerns as it was being halted by Germany.

For Vietnam, the war was to save the southern Vietnam territory from the insurgents up north who were supported by the USSR.

Thus,  the war was instrumental and defensive from their point of view.