What did the monroe doctrine prohibit european countries from doing

Which of these is true of that temperance movement at the beginning of the 1800’s in america?

Following archduke franz ferdinand's assassination, austro-hungarian leaders: a. aided the ottoman empire in its campaign to keep serbia under its control. b. executed nearly all prominent serbs living in austria-hungary c. threatened to invade serbia if serb leaders did not agree to a set of strict demands. d.. formed an alliance with great britain to protect austria-hungary from future attacks.

Why was the treaty of versailles harsh on germany?