Pick out the wrong statement.

A. Caustic embrittlement of boiler's metallic parts is caused by high concentration of caustic soda in boiler feed water

B. Cooling and freezing of water kills the bacteria present in it

C. With increasing boiler operating pressure of steam, the maximum allowable concentration of silica in feed water goes on decreasing

D. Dissolved oxygen content in high pressure boiler feed water should be nil

Answer: Option B