All of the following are guidelines for using the oil-immersion lens EXCEPT which statement?

A) Once the oil is applied and the oil-immersion objective lens is moved in place, focus the lens with the fine focus knob.
B) Once the oil-immersion lens is in place, swing the objective away from the slide and add a small drop of oil.
C) Place the slide on the microscope and focus first on low power, then medium and the high dry magnifications.
D) Once your slide is in position place a drop of oil on the slide and focus first at low power.