Answer:
The correct answer is B. The political party system that supported the campaigns of Barack Obama and John McCain is the two party system.
Step-by-step explanation:
A two party system is a system of political parties that favors the emergence of two political coalitions (usually antagonistic in the political spectrum) to generate an exclusion or positive discrimination of political minorities, happening in every election that one of them reaches the government of the nation and the other occupies the second place in the voting preferences, becoming the official opposition to the government. Its advocates argue that it generates political stability by excluding extremist sectors that could reach a parliamentary or presidential representation. On the contrary, his detractors argue that the fact that it excludes these minorities is undemocratic.