Refining using the liquation method is the most suitable for metals with a low melting point.
So, the correct option is (A): Low melting point.
In the given figure, the blocks $A$, $B$ and $C$ weigh $4\,\text{kg}$, $6\,\text{kg}$ and $8\,\text{kg}$ respectively. The coefficient of sliding friction between any two surfaces is $0.5$. The force $\vec{F}$ required to slide the block $C$ with constant speed is ___ N.
(Given: $g = 10\,\text{m s}^{-2}$) 
Method used for separation of mixture of products (B and C) obtained in the following reaction is: 
Refining is an industrial process of reducing the impurities of a substance. In simpler terms, refining is a process of purification of metals to remove the impurities from them to obtain the metals in the purest form.
There are various methods used in the refining process of metals. They are listed below-
Check: Zone Refining