Answer:
the U.S. play the role as big brother by bringing troops, guns, and supplies into Vietnam. they werent successful because they thought it would be like korea but instead it was a very mountainous terrain and heavily vegetated. also, the vc and north vietnamese army were a guerilla army which the us was not prepared for.
Explanation:
Yeah you are correct it's D. Prostent
The German U-boats blocked British Isle and attacked merchant ships affecting the trading business of US with British, but at some stage the U-boats started to attack ships taking the lives of unarmed passengers, as with the Lusitania ship, which 120 American died. The Germans were asked to stop the attacks but they did not and many US ships sank, shedding off US citizens lives. The submarine warfare enraged the US neutrality which then turned against the German and declared war on March 1 in 1917.