Which feature applies to the liquid cooling option available in some HP workstations?

A.
Reduces the toxicity of the cooling process

B.
Replaces the air passing over the heat sink with liquid

C.
Muffles the fan noise by surrounding the fan shroud with liquid

D.
Replaces the heat sink with a cold plate

Explanation:
http://www.asetek.com/press-room/news/2011/pc-liquid-cooling-comes-of-age-withasetek%E2%80%99s-sealed-systems.aspx