A Researcher Randomly Assigned Two Groups of 40 Students Each

A researcher randomly assigned two groups of 40 students each to read a vague passage. One group read a passage with a descriptive title that helped make sense of the passage. The other group read the same passage but without a title. The experimenter then tested students' memory of the reading by counting the number of ideas correctly recalled from the passage. In this study, the _____ is the dependent variable.

A) presence or absence of a title preceding the passage
B) number of ideas correctly recalled
C) individual differences in students' memory ability
D) number of students in the sample