If I understood your question correctly, then the answer is "it depends". Sometimes, individuals have a large impact on starting a war (think World War I where one individual caused the war to start), other times groups of people have also important roles in starting a war (think World War II).
The us government is a democracy
I would use D. Fact. Its about scientists so I would use some facts about them..
Running a Red Light or Stop Sign.
The conditions during the trip on sea was often hard and grueling, with disease being widespread and a lot of work to get done. Columbus's interactions with the Indians were not pleasant and many died from both sides.
