Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A): A good CI engine fuel, like diesel oil, is a bad SI engine fuel and a good SI engine fuel, like petrol, is a bad CI engine fuel.
Reason (R): A good CI engine fuel requires high self-ignition temperature and good SI engine fuel requires low self-ignition temperature.
In light of the above statements, choose the correct answer from the options given below.