Which choice correctly completes the sentence about horsepower?

• A. to increase
• B. to power
• C. to act
• D. to become

Answer: (D)

Infinitive phrases after a noun that describes capacity express the result something makes possible. Here, horsepower is about what the engine can achieve—that state it can reach. The phrase that conveys that potential state best is “to become,” signaling the engine’s ability to grow into a faster or more powerful performance. The other options don’t fit as neatly: “to increase” would need a target, “to power” repeats the idea of power in a clunky way, and “to act” assigns agency in a way that doesn’t match how horsepower describes capability.