Volatility of diesel fuel oil is_________________?

A. minimum temperature to which oil is heated in order to give off inflammable vapours in sufficient quantity to ignite momentarily when brought in contact with a flame
B. temperature at which it solidifies or congeals
C. it catches fire without external aid
D. indicated by 90% distillation temperature, i.e., when 90% of sample oil has distilled off
E. temperature at which it flows easily