Answer:
D. Change "he or she knows" to "they know."
Step-by-step explanation:
Pronouns are the words used to replace repeated nouns or used in place of nouns. They may be of the simple "he, she, it, they, them" form or may also be in the possessive form such as "himself, themselves, yourself, myself" etc.
In the given passage, the subject is "students" which is plural in number. The use of "he or she" in the sentence is not correct. This is because the pronoun for "students" cannot be a singular male or female subject, but a collective plural "they".
So, in place of the 'he or she' in the sentence, using 'they' will make the sentence correct and pronoun use valid. The pronouns used in the other parts of the sentence are also "they" and "their". Moreover, since the pronoun is plural, the verb will change from the singular "knows" to "know".
Now, the sentence becomes
When the students hear the school bell ring, they know they should be in class. If they are late, teachers ask to see their hall passes.
Thus, the best correction will be to change "he or she knows" to "they know."