Public opinion, political socialization, parties and/or media

modern technology such as social media allows for candidates to more easily connect to voters ... Having two major political parties represented. Coalitions.

a big wall across the mexican border so no drugs, terrorist, or illegal immigrants can come through : )    

the graph shows the spread of railways in the 1800s.

based on the graph, the conclusion that can be drawn about germany is answer d)   by 1880, germany had more rail lines than great britain and russia.