Which action by the US in the early 1960s deepened conflict in Vietnam?

restoring the former emperor to power
ignoring the concept of domino theory
supplying military advisers and weapons
not intervening after the assassination of the president

the answer to this question is the third option. hope this

united states reinforcements contributed greatly to three allied victories in france at: cantigny (first major american battle), argonne (the largest in the united states military history, involving 1.2 million american soldiers), and château-thierry (one of the first actions under general pershing).

b. would be the answer if not try c

hope this correct me if my answer is wrong if i am correct can you plz give me brainliest

: ) : 0 : o : d

explanation: