What is the primary characteristic of the Canadian Shield?

The primary characteristic of the Canadian Shield is its extensive mining and forestry. This region, which encompasses a large part of eastern and central Canada, is known for its rugged geological formation consisting of ancient, exposed rock. The Canadian Shield contains significant mineral resources, making it a hotspot for mining activities. Various minerals such as gold, nickel, copper, and diamonds are extracted from this area. Additionally, the dense forests found in the Canadian Shield region provide ample timber resources, supporting a robust forestry industry.

The other characteristics mentioned, such as high population density, rich agricultural land, or sea-level plains, do not accurately represent the Canadian Shield. The population in this region is relatively sparse due to its harsh climate and rugged terrain, making it less suitable for large-scale agriculture compared to other parts of Canada. The land's geological composition is not conducive to extensive farming, which is why mining and forestry are the prominent industries.