The ratio of Na2S to the sum of Na2S and Na2SO4 in green liquor expressed as a percentage. What s the name of the topic?

The ratio of Na2S to the sum of Na2S and Na2SO4 in green liquor expres

1.	The ratio of Na₂S to the sum of Na₂S and Na₂SO₄ in green liquor expressed as a percentage. What s the name of the topic?
A.	tSulfidity
B.	tCausticity
C.	tCausticizing efficiency
D.	tReduction efficiency
Answer» E.