1.) a filibuster to block a vote on a bill is possible
-only in the house, which is almost unrestrained
-only in the senate, which is almost unrestrained
-mostly in the house, but occasionally in the senate
-mostly in the senate, but occasionally in the house

a filibuster to block a vote on a bill is possible only in the senate which is almost unrestrained During a filibuster, the senates will argued about their decision regarding the bills until the decision was made. (without it, it is very common to conclude a discussion as 'unsolved' and leave it as it is until the next discussion is held)Hope this helps. Let me know if you need additional help!