Manuel's teacher asked the class to make a wet mount slide of their cheek cells. Manuel followed these procedures after scraping his mouth with a toothpick before observing the cells. 1. rubbed toothpick in water drop on glass microscope slide 2. placed slide on microscope stage 3. held slide in place with stage clips 4. first turn nose piece so low power objective was positioned over slide In this sequence of tasks, what important step did Manuel forget?

A) cover the water drop with a cover slip
B) raise the objective as high as possible
C) use cloth or lab coat to wipe lens in eye piece
D) turn nose piece so high power objective is over water drop