Which sentence correctly uses parallel structure? The boss wants to know who can take the late shift tonight, open tomorrow morning, and who can work on the holiday. The boss wants to know who wants the late shift tonight, who can open tomorrow morning, and if you will work on the holiday. The boss wants to know who can take the late shift tonight, who can open tomorrow morning, and who can work on the holiday. The boss wants to know who can take the late shift tonight, who can open tomorrow morning, and which of us wants to work on the holiday.

The answer is:

The boss wants to know who can take the late shift tonight, who can open tomorrow morning, and who can work on the holiday.

Parallelism is the balance between two or more clauses or phrases with the same grammatical construction, and makes sentences easier to read.

In the sentence that uses a correct parallel structure, there is a similarity in the the phrases "who can take the late shift tonight, who can open tomorrow morning, and who can work on the holiday." The reason is the three clauses use the same relative pronoun "who," the modal verb "can" and the following verb in an infinitive form.

C) The boss wants to know who can take the late shift tonight, who can open tomorrow morning, and who can work on the holiday.