In spark ignition petrol engines maximum emission of Nox takes place when the air fuel ratio (A/F) is
A
Very weak mixture and A/F ratio about 19
B
Weak mixture and A/F ratio about 17
C
Chemically correct mixture and A/F ratio about 15
D
Rich mixture and A/F ratio about 13.
Correct Answer: Chemically correct mixture and A/F ratio about 15