1 ptsD,D1Official number: 6928
What causes ignition in a diesel oil?

Explanation
Correct answer: High temperature of the air.
A diesel engine is a compression-ignition engine, which means it does not use spark plugs. In the cylinder, air is compressed to a very high pressure, causing a rapid increase in its temperature. The injection of fuel (diesel fuel) into this highly heated air results in its spontaneous ignition, which sets the engine in motion.