These staff members with drafting bills and doing research.
a. administrative assistants
c. committee staff
b. legislative assistants
d. case workers

(b) Legislative Assistants; A legislative assistant (LA) is a legislative staffer who works for a legislator by monitoring pending legislation, conducting research, drafting legislation, giving advice and counsel, and making recommendations. Other job duties include generating ideas for legislation, writing speeches delivered to a committee or legislature, e.g. the U.S. Congress or a state legislature.