The correct answer is option 3: Florida current. The Labrador current is a cold ocean current that flows from the Arctic Ocean south along the coast of Labrador and Newfoundland in Canada. It carries cold, nutrient-rich water from the Arctic region and influences the climate and marine life in the area it flows through.

The Florida current, on the other hand, is a warm ocean current that flows northward off the east coast of Florida in the United States. It is part of the larger Gulf Stream system and originates in the Caribbean Sea. The Florida current is warm and carries warm water from the tropics towards the North Atlantic.

These two currents, the Labrador current and the Florida current, interact and mix in the North Atlantic Ocean. The warm water from the Florida current meets the cold water from the Labrador current, creating a dynamic oceanic system with varying temperatures and nutrient distribution. This mixing zone is important for the marine ecosystem and plays a role in the transport of heat and nutrients around the Atlantic Ocean.

In summary, it is the Florida current that mixes with the Labrador current in the North Atlantic Ocean.