【简答题】
一个酯(M=116)的质谱图有显著的m/z 57(100%),m/z 29(57%),m/z 43(27%)峰,其结构为( )<br> A.(CH<sub>3</sub>)<sub>2</sub>CHCOOCH<sub>2</sub>CH<sub>3</sub> B.CH<sub>3</sub>CH<sub>2</sub>COOCH<sub>2</sub>CH<sub>2</sub>CH<sub>3</sub><br> C.CH<sub>3</sub>CH<sub>2</sub>CH<sub>2</sub>COOCH<sub>3</sub> D.CH<sub>3</sub>CH<sub>2</sub>CH<sub>2</sub>CH<sub>2</sub>COOCH<sub>3</sub><br/>A.(CH<sub>3</sub>)<sub>2</sub>CHCOOCH<sub>2</sub>CH<sub>3</sub><br/>B.CH<sub>3</sub>CH<sub>2</sub>COOCH<sub>2</sub>CH<sub>2</sub>CH<sub>3</sub><br><br/>C.CH<sub>3</sub>CH<sub>2</sub>CH<sub>2</sub>COOCH<sub>3</sub><br/>D.CH<sub>3</sub>CH<sub>2</sub>CH<sub>2</sub>CH<sub>2</sub>COOCH<sub>3
A、A.(CH3)2CHCOOCH2CH3
B.CH3CH2COOCH2CH2CH3
C.CH3CH2CH2COOCH3
D.CH3CH2CH2CH2COOCH3