单项选择题

试验室中常用的铬酸洗液是指()

A.K<sub>2</sub>Cr<sub>2</sub>O<sub>7</sub>+浓H<sub>2</sub>SO<sub>4</sub>
B.K<sub>2</sub>Cr<sub>2</sub>O<sub>7</sub>+浓HCl  
C.K<sub>2</sub>Cr<sub>2</sub>O<sub>4</sub>+浓H<sub>2</sub>SO<sub>4</sub> 
D.K<sub>2</sub>Cr<sub>2</sub>O<sub>4</sub>+浓HCl