The soldier of Napolean army while at Alps during freezing winter suffered a serious problem as regards to the tin buttons of their uniforms. White metallic tin buttons got converted to grey powder. This transformation is related to :

Options

A. an interaction with nitrogen of the air at very low temperature
B. a change in the crystalline structure of tin
C. an interaction with water vapour contained in the humid air
D. a change in the partial pressure of oxgen in the air .

Answer

B