单项选择题

A. SELECT SNO,CNO,SCORE  FROM G WHERE CNO=C1 AND CNO=C2
B. SELECT SNO,CNO,SCORE  FROM G WHERE CNO=C1 OR CNO=C2
C. SELECT SNO,CNO,SCORE  FROM G WHERE CNO=”C1” AND CNO=”C2”
D. SELECT SNO,CNO,SCORE  FROM G WHERE CNO=”C1” OR CNO=”C2”