A school nurse is performing vision screenings for a group of students to check ocular alignment using the cover test. Which of the following instructions should the nurse give to the students?

"Read the words on this paper while I quickly move a cover from one eye to the other.”.

"Look straight ahead and try not to blink while I shine this light into your eyes.”.

"Focus on the finger I am holding up while I cover one eye, and then the other.”.

"Cover your left eye and use your right eye to read the letters I point to on this chart.”.