Final answer:
A proposed piece of legislation is called a bill (option e). A bill may be subjected to a filibuster by a legislature's unlimited debate, and the debate can only end with a cloture motion supported by a supermajority.
Step-by-step explanation:
The correct answer to the question about what a proposed piece of legislation is called is e. bill. A bill is proposed legislation that is under consideration by a legislature. If a member of the legislature insists on unlimited debate on a bill, this is known as a filibuster.
The only way for the debate to end and for the bill to come to a vote is if a supermajority, typically three-fifths of senators in the U.S. Senate, which amounts to 60 out of 100, vote for a cloture motion. Therefore, the cloture process is an essential tool for managing and limiting debate to allow legislative business to proceed.