Read the Following Argument and Use It to Answer Question

Read the following argument and use it to answer question
Claim: Athletes receive preferential treatment in some classes.
Grounds: Members of the basketball team are allowed to miss classes without incurring the penalties imposed on non-athletes who miss classes.
Warrant: These conditions suggest preferential treatment of the athlete over the nonathlete by some professors.
Backing: Preferential treatment in the classroom is commonly recognized as being allowed to miss classes without penalty and being allowed to make up exams that have been missed.
-The type of evidence used as grounds in the argument stated above is

A) an example.
B) a premise.
C) an opinion.
D) a scientific report.