Which diving technique is enhanced by using EANx?

Using Enriched Air Nitrox (EANx) has significant applications in technical diving, making it the best choice among the options provided. Technical diving often involves deeper and longer dives, where the management of nitrogen absorption and the risks of decompression sickness are critical. By using EANx, divers can reduce the amount of nitrogen in their breathing mix compared to regular air, which allows for longer no-decompression limits and decreases the risk of nitrogen narcosis.

The higher oxygen content in EANx also provides an advantage due to its potential to enhance the diver's performance at depth and aid in better physical conditioning during the dive. Additionally, the reduced nitrogen load helps with faster surface intervals and shorter decompression stops, which are essential elements in technical diving.

While other diving techniques like free diving, wreck diving, and night diving can certainly benefit from different equipment and practices, they do not specifically leverage the advantages of EANx in the same way that technical diving does. Thus, EANx's role in technical diving is unparalleled, making it the most appropriate answer.