What is the meaning of reinforce?

• A. To support an idea by giving evidence or reasons
• B. To enhance something
• C. To make something stronger
• D. To weaken

Answer: (C)

The main idea is the meaning of reinforce: it means to make something stronger or more solid. You can use it for physical things, like adding supports to a structure so it holds up better, and you can use it for ideas, where you reinforce a point by providing evidence or reasons that strengthen your argument. That direct sense of increasing strength is why the answer is to make something stronger. Other senses exist—such as enhancing quality or supporting an idea with evidence—but they’re either broader or more specific ways of strengthening rather than the core meaning itself, and clearly opposite meanings like weakening don’t fit.