Final answer:
The 5th Fleet's area of responsibility is the Middle East and the Red Sea, where it ensures regional security and stability.
Step-by-step explanation:
The area of responsibility for the 5th Fleet is c) Middle East and Red Sea. This naval command is tasked with maritime operations to ensure security and stability in this strategic region, which encompasses key maritime chokepoints and vital sea lanes of communication. The region is crucial not only for its geopolitical significance but also for the global economy, given the vast amount of oil that transits through the Arabian Gulf.