Who is responsible for ensuring compliance with airport security regulations?

The Transportation Security Administration (TSA) is designated as the authority responsible for ensuring compliance with airport security regulations. This federal agency was established primarily to enhance the security of the nation's transportation systems, including airports and aviation. The TSA develops and enforces security measures at airports, oversees passenger screening processes, and regulates security protocols for airlines and airport operators. Its comprehensive approach to aviation security includes coordinating efforts with various stakeholders while ensuring adherence to federal security guidelines.

In contrast, the Federal Aviation Administration (FAA) is primarily focused on regulating civil aviation, which includes responsibilities for the safety of aircraft operations and the safety of the airspace system. The National Transportation Safety Board (NTSB) serves as an independent agency tasked with investigating transportation accidents and making safety recommendations, rather than overseeing compliance regulations. Airports Council International (ACI) is a global trade representative of airport authorities, which works to improve airport operations and performance but does not have regulatory authority over airport security measures. Therefore, the TSA's central role in implementing and managing airport security regulations makes it the correct answer.