The answer is A. horns.
A horn is a pyramidal peak formed by the intersection of three or more cirques. Cirques are steep-walled amphitheaters carved out by glaciers. As the glacier moves down the mountain, it erodes the rock, creating a bowl-shaped depression. The cirque walls are often very steep, and the floor of the cirque is usually filled with talus, which is a loose accumulation of rocks and boulders.
When several cirques form on a mountain, they can intersect to create a horn. Horns are often very sharp and pointed, and they can be very dangerous to climb. However, they are also very beautiful, and they are a popular destination for mountaineers.
Here is a brief explanation of each option:
- A horn is a pyramidal peak formed by the intersection of three or more cirques.
- A cirque is a steep-walled amphitheater carved out by glaciers.
- An arete is a sharp ridge formed by the intersection of two cirques.
- A medial moraine is a ridge of debris that forms in the middle of a glacier.