You're creating a video ad for a restaurant chain with the goal of driving reservations on its website. Which of the following call-to-actions (CTAs) should you use in the ad?

Book now" is the most effective CTA because it directly aligns with the goal of driving reservations. It clearly instructs users on the desired action. "Check us out" is too vague and doesn't encourage a specific conversion. "Learn more" is also too generic and implies further research rather than an immediate action like booking. "Call now" might be suitable if the primary conversion was phone reservations, but the goal specifies driving reservations on its website, making "Book now" the most direct and relevant option for an online conversion.