There Are Three Conditions in Makeba's Research Study

There are three conditions in Makeba's research study. As people enter the lab, Makeba draws a number between 1 and 3 out of a hat and gives them a research packet that matches that number. What is Makeba doing by drawing the number from the hat?

A) She is performing random assignment.
B) She is introducing a dependent variable.
C) She is using a covert measure.
D) She is collecting observational data.