Think of it this way,
Mix Iron and sulphur in a bowl. How do you separate them? Use a magnet right. Yes.
Now, mix the iron and sulphur together but know, heat them up. Let them cool for a while. After that, use a magnet to separate. You cant. This is because the compound (FeS) now has a different property from its original components.
Apply this theory onto salts.
The best quality answer I would say that it is cC
the line graphs and pie charts are used for different kinds of analysis
a) pie chart : it compares the portion of one thing in a group of different things
For example out of 100 people how many have brown hairs , how many have black hairs and how many have white hairs
or
like population division out of 100 into different parts
b) line graphs: they show the relation ship between two variables
Example: effect of temperature on volume
it tells the trend in any property with respect to some other quantity or quality parameter.