Which of the following is considered a new challenge in aviation?

Unmanned Aerial Vehicles (UAVs) represent a significant new challenge in aviation due to their increasing presence in both commercial and recreational airspace. The integration of UAVs into the aviation system raises numerous concerns ranging from airspace management and safety to regulatory and operational issues.

As UAV technology evolves and becomes more accessible, airports and air traffic control systems must adapt to accommodate these vehicles, which operate differently from traditional aircraft. This includes establishing specific guidelines to ensure that UAVs can safely coexist with manned aircraft, as well as addressing potential security risks they may pose.

The other options, while related to the aviation industry, are not new challenges. Increased airline ticket prices are a recurring issue influenced by factors like fuel costs and demand fluctuations, and the standardization of passenger service regulations is part of ongoing efforts to streamline the travel experience. Additionally, the reduction of airport security measures is generally viewed as a regression rather than a new challenge, as post-9/11 security measures have been continuously adapted rather than reduced.