单项选择题
The chemical shifts of the marked hydrogen nuclei in the following compounds should be：
A、
a :1.5~2.0 ppm, b amd c : 1.8~3.0 ppm, d : 9.0~10.0 ppm;
B、a :1.5~2.0 ppm, b amd c : 5.5~7.5 ppm, d : 10.0~15.0 ppm;
C、
a :0~1 ppm, b amd c : 5.5~7.5 ppm, d : 9.0~10.0 ppm;
D、a :1.5~2.0 ppm, b amd c : 5.5~7.5 ppm, d : 9.0~10.0 ppm.
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