Function of an enzyme is to lower reaction's activation energy and to increase speed of a reaction, but to make it happen, enzyme and substrate must fit spatially. The shape of an enzyme is essential to make enzyme-substrate complex - if active site of an enzyme doesn't fit to substrate, there won't be a enzyme-catalised reaction.
The answer is B. The specific heat means the heat amount the substance needs to absorb when the temperature increases 1℃. The high specific heat means that it needs a huge amount of heat when increase just 1℃. For A, the dissolved salts can help decrease the freezing point.
