Which Conclusion Is Supported by Research Comparing "Successful" to "Unsuccessful

Multiple Choice

Which conclusion is supported by research comparing "successful" to "unsuccessful" students

A)  Successful students and unsuccessful students attended class equally often. 
B)  Successful students attended class more often than unsuccessful students. 
C)  Successful students used an instructor's office hours more than unsuccessful students. 
D)  Successful students made better use of the textbook than did unsuccessful students.