The correct answer is: C. levigation
Levigation is a process of separating ore from impurities based on their different densities. The ore is mixed with water and then agitated. The lighter impurities float to the top and are skimmed off, while the heavier ore sinks to the bottom.
Liquation is a process of separating metals from their ores by melting them and then allowing them to solidify. The metals with lower melting points will melt first and can be separated from the other metals.
Leaching is a process of dissolving ore in a solvent. The ore is mixed with a solvent that dissolves the ore but not the impurities. The solution is then filtered to remove the impurities, and the ore is left behind.
Magnetic separation is a process of separating magnetic materials from non-magnetic materials. The ore is mixed with a magnetic field, and the magnetic materials are attracted to the magnet and can be separated from the non-magnetic materials.