On the First Day in His New School, Mario Dressed

On the first day in his new school, Mario dressed the way he had at his old school, in shorts and a casual shirt. He received stares from other students, who were mostly dressed in khakis and polo shorts. Why did the others stare at Mario

A) He violated social norms.
B) He was disobedient.
C) He was a nonconformist.
D) He did not comply with explicit expectations.