Which fleet is responsible for operations in Central and South America?

The 4th Fleet is indeed responsible for operations in Central and South America. This fleet is focused on maritime security, humanitarian assistance, and joint operations with partner nations in this region. Its operational responsibilities include a wide range of missions that promote regional stability and respond to crises, making it particularly relevant for areas such as the Caribbean and South America.

The other fleets, while also vital components of the United States Navy's global operations, have different areas of responsibility. The 5th Fleet primarily operates in the Arabian Gulf, Red Sea, and surrounding areas; the 6th Fleet covers the Mediterranean Sea and parts of the Black Sea; and the 3rd Fleet operates primarily in the eastern Pacific Ocean. Each fleet has distinct geographical areas of focus, which underlines why the 4th Fleet is the correct answer for operations specifically in Central and South America.