Answer:
D. Pure vegetable oil.
Step-by-step explanation:
The smoking point is the temperature at which the fat or oil began to smoke before reaching its boiling point. The smoking point increase with decrease in fatty acid content and the act of heating oil or fat produces more fatty acids thus decreasing the smoking point.
The smoking point of liquefied lard is 370°F.
The smoking point of bacon grease or bacon fat is 325°F.
the smoking point of pure vegetable oil is 400°F.
The reused vegetable oil has high number of fatty acids which is likely to decrease its smoking point in proportion to number of times it is reused.