The chemical property deals with the ability of a substance being able to burn is called combustibility [ option b ] .
More to know :-
1) Combustion :-
Combustion is a chemical process in which a substance reacts rapidly with oxygen and gives out heat.
The fuel can be any one of the 3 states of matter that is - solid , liquid & gases .
Examples of combustible substances :-
Solid - Coal
Liquid - Petrol , Disel , etc.
Gas - Hydrogen , Oxygen , etc .