理想运放的开环差模电压增益, 共模电压增益应不完全准确的是（        ）。

A、<span style="font-size:16px;font-family:楷体_GB2312">∞</span> <span style="font-size:16px;font-family:楷体_GB2312">，∞</span>

B、<span style="font-size:16px;font-family:楷体_GB2312">∞</span> <span style="font-size:16px;font-family:楷体_GB2312">，</span><span style="font-size:16px;font-family:&#39;Times New Roman&#39;,&#39;serif&#39;">0&nbsp;</span>

C、<span style="font-size:16px;font-family:&#39;Times New Roman&#39;,&#39;serif&#39;">0</span><span style="font-size:16px;font-family:楷体_GB2312">，</span> <span style="font-size:16px;font-family:楷体_GB2312">∞</span>

D、<span style="font-size:16px;font-family:&#39;Times New Roman&#39;,&#39;serif&#39;">0</span><span style="font-size:16px;font-family:楷体_GB2312">，</span><span style="font-size:16px;font-family:&#39;Times New Roman&#39;,&#39;serif&#39;">0</span>