Exam 312-50v12 topic 1 question 240 discussion

As an IT intern, you have been asked to help set up a secure Wi-Fi network for a local coffee shop. The owners want to provide free Wi-Fi to their customers, but they are concerned about potential security risks. They are looking for a simple yet effective solution that would not require a lot of technical knowledge to manage. Which of the following security measures would be the most suitable in this context?