Carbon can be used to reduce the number of oxides and other compounds, and because of the low cost and availability of coke, this method is widely used. But the disadvantages are that:

Example:

$ZnO+C\stackrel{1200^{\circ }C}{\to }Zn$ 

But the disadvantage of this method are that a high temperature is needed, which is expensive and requires the use of a blast furnace. And many metals combine with carbon, forming carbides. 

Hence, the correct options are (A) and (B).