Match the following

	List - I (Concentration method)		List - II (Principle)
A.	Hydraulic washing	a.	Difference in solubility of gangue and ore particles in a specific substance
B.	Magnetic separation	b.	Difference in wetting property of ore and gangue particles
C.	Froth flotation	c.	Difference in gravities of ore and gangue particles
D.	Leaching	d.	Difference in magnetic property of gangue and ore particles

The correct match is

	A	B	C	D
1.	b	d	c	a
2.	a	b	c	d
3.	a	d	b	c
4.	c	d	b	a

Hydraulic washing : This method is also called gravity separation or levigation. It is based on the difference in specific gravities of the ore and gangue particles

Magnetic separation : This method is used if the gangue or the ore particles are magnetic in nature.

Froth flotation : This process is based on different wetting properties of gangue and the ore with water and oil.

Leaching : In this method, the powdered ore is treated with certain reagents in which the ore is soluble but the impurities are not soluble.