Question

Which revision eliminates the pronoun shift in the sentence below? if a student wishes to go on the field trip, they must bring in a permission slip. if a student wishes to go on the field trip, you must bring in a permission slip. if students wish to go on the field trip, he or she must bring in a permission slip. if students wish to go on the field trip, you must bring in your permission slips. if a student wishes to go on the field trip, he or she must bring in a permission slip?

Answer 1

D) If a student wishes to go on the field trip, he or she must bring a permission slip :)

Answer 2

Answer;
If a student wishes to go on the field trip, he or she must bring in a permission slip. 

Explanation; 
This is because a singular noun, student, should take a singular pronoun, and the subject must agree with the verb. That is; instead of using the noun student (singular noun) with the pronoun they (plural pronoun), one should use the pronouns he or she (singular pronoun)