问题：
[单选题]假设参加计算机等级考试的学生关系R，参加英语等级考试的学生关系S。求既参加了计算机考试又参加了英语考试的学生，应当进行下列（）。
A、R-S
B、R+S
C、R∪S
D、R∩S
参考答案：
D
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