Which action can increase security in public spaces at airports?

Implementing baggage checks significantly increases security in public spaces at airports by ensuring that any items being transported by passengers are screened for potential threats. This process helps identify prohibited items or dangerous materials that could compromise safety. By thoroughly inspecting bags and personal belongings before they reach the boarding area, potential risks are mitigated, thereby enhancing the overall security environment.

In addition to this, the presence of baggage checks serves as a deterrent to individuals who might consider carrying harmful items into the airport, as they know that their belongings will be subject to scrutiny. This layered approach to security not only addresses immediate threats but also builds a culture of safety and vigilance among passengers and airport staff alike.

The other options do not contribute effectively to enhancing security. For instance, reducing security presence would lower the overall protection available, while providing more waiting areas does not address potential security vulnerabilities, and allowing free access for all could invite more security risks rather than mitigate them.