Auto-ignition temperature 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) that at which it catches fire without external aid
(D) indicated by 90% distillation temperature, i.e., when 90% of sample oil has distilled off
(E) indicated by 50% distillation temperature

