Dr. obsessa compulsa was a meticulous researcher. to make sure her assistants did not give any hints regarding which participants were in which treatment groups and to make sure her participants did not know which group they were in, she employed a:

Double-blind study  

A double-blind study is a type of experiment where neither the participants nor the researchers know which individuals belong to the test group and which ones belong to the control group.

It is a particularly stringent way of conducting research, and it is meant to eliminate as much bias as possible from the results of the study.

answer; /// the only one thats make little sense is (c) fair credit billing act;

all of them lol cause theres no map