[单选题]Miss Yang tries her best to create a relaxing atmosphere in her classes, ________students can study happily.
A.when
B.which
C.where
D.that

参考答案:C

【详解】
考查定语从句。句意：杨老师尽力在课堂上营造一种轻松的氛围，让学生们可以快乐地学习。分析句子结构可知，“Miss Yang tries her best to create a relaxing atmosphere in her classes”是主句，“________students can study happily.”是非限定性定语从句，先行词是atmosphere(氛围)，且定语从句中缺少状语，即in the atmosphere，应用关系副词where来引导，故选C。