Final answer:
The parliament chosen by the Vorparlament for drawing up a constitution for a united Germany was decided to be elected through universal manhood suffrage.
Step-by-step explanation:
The Vorparlament, a gathering of leaders within the German Confederation, reached an agreement on how to elect a national parliament that would draw up a constitution for a united Germany. They decided that the parliament would be chosen via universal manhood suffrage, meaning that all adult men would have the right to vote. This parliament met in Frankfurt with the intention of writing a constitution to unify the German states into one nation.