A Researcher,who Predicts That Left-Handers Are Better Artists Than Right-Handers,watches

Multiple Choice

A researcher,who predicts that left-handers are better artists than right-handers,watches people draw and evaluates their art.What would be the most important way to improve this study?​

A) Randomly assign people to being left- or right-handed.
B) ​Evaluate their music as well as their art.
C) ​Use a "blind" observer.
D) ​Be sure to have an equal number of left- and right-handers.