What was one of the motivations for British support of Canadian Confederation?

One motivation for British support of Canadian Confederation was to reduce military expenditures in the colonies. During the mid-19th century, there was growing concern in Britain about the security of its North American territories. The colonies faced threats from the United States, among other vulnerabilities, which meant that maintaining a military presence to defend them was costly. By encouraging the confederation of these colonies, Britain aimed to create a more self-sufficient and united entity that could manage its own defense. A unified Canada would be better positioned to develop its military capabilities and assume more responsibility for its own security, thus relieving Britain of some of the financial burdens associated with defending the individual colonies against potential threats.

The other options represent different aspects of historical context but do not directly align with the motivations behind British support for Confederation at the time. Enhancing trade with European nations, for example, was not a primary focus for Britain; instead, it was more interested in maintaining stability in its colonies. The idea of establishing a united monarchial system was already in place under British rule, and promoting independence movements would have been contrary to British interests, as they sought to maintain control over the colonies rather than encouraging movements that could weaken their authority.