The Influence of National Forces in Congressional Elections ______

The influence of national forces in congressional elections ______.

A) only matters in Senate elections since senators are elected statewide.
B) matters because the correlation between the vote share of congressional candidates and presidential candidates at the state and district levels has increased and so congressional elections are treated as national events.
C) has declined in recent years as incumbents have gotten much better at separating themselves from the collective fate of their parties.
D) does not really matter because House and Senate candidates have developed sophisticated campaign strategies that allow them to win seats in the other party's presidential territory.