Which of the following statements best describes the impact of a valuation allowance on the financial statements A valuation allowance:（）

A. increases reported income, reduces assets, and reduces equity.  

B. reduces reported income, reduces assets, and reduces equity.  

C. increases reported income, increases liabilities, and reduces equity.

水、电、气三基表电脉冲信号由数据采集器再由总线传输到物管中心微机。