What Is the Relationship Between the Management of Casework and Re-Election

What is the relationship between the management of casework and re-election to Congress?

A) Senators who effectively manage casework have a better chance of re-election than members of the House who also effectively manage casework.
B) Being able to effectively manage casework improves the chances of members in both the House and the Senate of being re-elected.
C) Effectively managing casework can backfire on members of Congress if their constituents perceive their efforts to be too focused.
D) Members of Congress who effectively manage casework only have a small advantage during an election against a challenger.