Answer: B) You are to continue heating the round-bottom flask until all liquid has been distilled.
Step-by-step explanation:
Fractional distillation refers to a method that's useful for the separation of mixtures of solvents whereby there is less than 40°C in the boiling point difference.
With regards to the options given, the incorrect statement about the procedure for distillation is that you are to continue heating the round-bottom flask until all liquid has been distilled. This isn't correct.