Deficiency of combustion air during combustion of a gaseous fuel

Question: Deficiency of combustion air during combustion of a gaseous fuel
[A].

lengthens the flame.

[B].

causes heat loss of fuel by its partial combustion.

[C].

both (a) & (b).

[D].

shortens the flame.

Answer: Option C

Explanation:

No answer description available for this question.