Black smoke coming out of the chimney of a furnace is an indication of the use of __________ in the furnace.

Question: Black smoke coming out of the chimney of a furnace is an indication of the use of __________ in the furnace.
[A].

low amount of excess combustion air

[B].

large quantity of excess combustion air

[C].

hydrocarbon fuel

[D].

pulverised coal as fuel

Answer: Option A

Explanation:

No answer description available for this question.