Final answer:
The most effective call to action for Bill on social media to increase bookings would be offering a discount to encourage immediate bookings.
Step-by-step explanation:
To increase his bookings through a social media posting, Bill, who owns a small, local video production company, should use an effective call to action that prompts immediate response and delivers a clear incentive to potential customers.
Among the given options, the most effective call to action is 'b. "Book our video production services now for a discount!"' This message not only encourages immediate action with the word 'now' but also provides an attractive incentive in the form of a discount, which is likely to spur potential clients into action.
The most effective call to action for Bill's social media posting would be option b. "Book our video production services now for a discount!" This message creates a sense of urgency and offers an incentive for potential customers to take immediate action. By providing a discount, Bill is more likely to increase his bookings as people are more likely to respond to an offer that provides them with a benefit.