Who was the most important investor in the CPR and also a major shareholder in the HBC?

The correct choice identifies Donald Smith as the most important investor in the Canadian Pacific Railway (CPR) and a major shareholder in the Hudson's Bay Company (HBC). Donald Smith, later known as Lord Strathcona, played a pivotal role in financing and supporting the CPR project, which was vital for connecting Canada's eastern and western regions. His involvement was crucial during a time when Canada was working towards its nation-building efforts.

Smith’s considerable financial investments helped ensure the railway's completion, which not only facilitated trade and travel across the country but also played a significant role in the overall development and economic growth of Canada. His status as a prominent figure in both the railway and the Hudson's Bay Company highlights his influence in Canadian commerce and infrastructure during that era.

The other figures mentioned, while significant in their own right, did not carry the same weight of investment or direct involvement in these two major business ventures. William Van Horne was the general manager of the CPR and contributed to its construction but was not the primary investor. John A. Macdonald, as Canada's first Prime Minister, facilitated the railway's creation but was not an investor. George Stephen was also a prominent figure within the CPR, but Donald Smith's broader financial role made him the key investor