Which of the following is a tactic used by a senator to stall a bill and prevent a vote?
a. filibuster
c. incumbent
b. duster
d. candidate

a. filibuster

Explanation:

Obstruction is a mechanism commonly used by opposition parliamentarians and minority groups to create obstacles to delay or prevent voting and the consequent adoption of a government bill. This does not constitute any kind of crime, it is only an instrument available in democracy in presidential regimes, as in the USA. Normally, after an agenda is obstructed, parliamentarians negotiate and arrange for the agenda to be approved.

answer; analytical;