A Vice Principal Has Good Reason to Believe That a Certain

A vice principal has good reason to believe that a certain pocket of a student's book bag contains a handgun. He searches the pocket and finds bullets, but no gun. From a legal standpoint, he probably

A) has no right to search further, since he did not find a gun.
B) should avoid accusing that individual student and should consider a search of all students in the school until the gun is found.
C) has sufficient evidence to confirm his suspicion and to suspend the student.
D) has reasonable suspicion to search the bag more extensively.