Context: Read the passage and look at the picture.
The Reykjanes Ridge is part of the Mid-Atlantic Ridge, a mid-ocean ridge that is mostly under water. The Reykjanes Ridge is one place where the Mid-Atlantic Ridge is above water. The Reykjanes Ridge runs through Iceland, an island country in the North Atlantic Ocean. The ridge began to form millions of years ago as the North American Plate and the Eurasian Plate started to move apart. Visitors to Thingvellir National Park in Iceland can actually walk in the space between the North American Plate and the Eurasian Plate!
Complete the sentence.
The Reykjanes Ridge formed at a () boundary.
A. divergent
B. convergent
C. transform
Identify the correct choice from the options below and respond with the letter of the correct option.

A