Anderson Is Reading His Morning Paper and Sees the Following

Multiple Choice

Anderson is reading his morning paper and sees the following headline: "Men Should Avoid Rock Music When Playing Board Games." (This headline is based on a study conducted by Fancourt, Burton, & Williamon, 2016.) In the study, men and women played the game "Operation" when listening to different types of music. Male participants performed worse when listening to AC/DC than when listening to Mozart, but female participants' performance did not differ based on music.
In this study, the researchers recorded how many errors participants committed. This is an example of which of the following?

A) a constant
B) a variable's level
C) a measured variable
D) a manipulated variable