Efficiency of the combustion of a fuel is judged by the __________ the flue gas.

Question: Efficiency of the combustion of a fuel is judged by the __________ the flue gas.
[A].

%of CO2 in

[B].

% of O2in

[C].

temperature of

[D].

colour of

Answer: Option B

Explanation:

No answer description available for this question.