Consider the following statements with regard to IC engines:1. For best fuel economy of spark ignition engines, the fuel-air mixture should be lean2. With supercharging, the specific consumption in compression ignition engines increases3. With increase of load, knocking tendency in compression ignition engines increasesWhich of the above statements are correct?

Consider the following statements with regard to IC engines:1. For bes

1.	Consider the following statements with regard to IC engines:1. For best fuel economy of spark ignition engines, the fuel-air mixture should be lean2. With supercharging, the specific consumption in compression ignition engines increases3. With increase of load, knocking tendency in compression ignition engines increasesWhich of the above statements are correct?
A.	1 and 2 only
B.	2 and 3 only
C.	1 and 3 only
D.	1, 2 and 3
Answer» D. 1, 2 and 3