What is the main purpose of Canada's Constitution?

The main purpose of Canada's Constitution is to outline the structure of government and the rights of citizens. This foundational document serves as the supreme law of Canada, establishing how the government operates, the distribution of powers between different levels of government (federal and provincial), and the rights and freedoms guaranteed to Canadian citizens.

The Constitution plays a critical role in ensuring that the government functions within a legal framework that protects individual liberties and promotes justice. It sets the ground rules for how laws are made and interpreted and underpins the democracy of Canada by ensuring that citizens have a voice in their governance.

The other choices focus on specific aspects of governance or international relations that are indeed important but are not the primary purpose of the Constitution itself. For example, while defining the responsibilities of the provinces is a component of the Constitution, it is part of the broader goal of outlining government structure. Similarly, establishing international relations or setting trade regulations are important areas of governance but fall outside the core objectives of the Constitution.