Depending on the behaviour of the coal, when it is heated in the absence of air, it can be categorized into ______ categories.

Depending on the behaviour of the coal, when it is heated in the absen

1.	Depending on the behaviour of the coal, when it is heated in the absence of air, it can be categorized into ______ categories.
A.	2
B.	3
C.	4
D.	5
Answer» B. 3