The cold ocean current which meets the warm Gulf Stream between latitudes 40° and 43°N to form the "cold wall" is called the __________.

Correct Answer: Option C — Labrador Current

The cold, southward-flowing Labrador Current meets the warm, northward-flowing Gulf Stream off the Grand Banks of Newfoundland between 40° and 43°N, establishing a sharp temperature gradient known as the "cold wall," as detailed in navigational oceanography references in Bowditch.