Which option preserves parallel structure in the list of actions in infinitives?

Which option preserves parallel structure in the list of actions in infinitives?

• A. to launch a campaign, hire new staff, and to expand operations
• B. launching a campaign, hiring new staff, and expanding operations
• C. to launch a campaign, to hire new staff, and to expand operations
• D. to launch a campaign, hire new staff, and to expanding operations

Answer: (C)

Parallel structure means the items in a list share the same grammatical form, so the sentence reads smoothly and clearly. When listing actions that are expressed as infinitives, each item should be the same infinitive form: to + base verb. That keeps the rhythm steady and makes the sequence easy to follow: to launch a campaign, to hire new staff, to expand operations.

Other forms break the pattern. Using bare verbs like hire without to mismatches with the to-launch and to-expand, which disrupts the flow. Using -ing forms like launching, hiring, expanding moves the list away from infinitives entirely, changing the grammatical pattern. And mixing to with a noninfinitive like to expanding is ungrammatical, since after to the verb should remain in base form, not the -ing form.

So the sentence with all three items in the to + base verb infinitive form preserves the parallel structure best.