What major change occurred for Britain regarding shares after 1869/75?

In the context of British economic and colonial strategy during the late 19th century, a significant development occurred with respect to the Suez Canal Company. Between 1869 and 1875, Britain made a strategic decision to acquire a controlling stake in the Suez Canal, which was a vital trade route connecting Europe to Asia. The purchase of majority shares in the company allowed Britain to secure its interests in this essential maritime passage, thereby strengthening its economic position and enhancing its control over international trade routes.

This move was part of a broader trend during this period when British imperial ambitions were at their peak. Controlling the canal was not only about securing trade advantages but also about demonstrating British naval power and extending its influence in global affairs. The acquisition of these shares was a calculated response to growing competition from other nations and a recognition of the strategic importance of the Suez Canal in facilitating British trade and communication with its colonies and other markets.

The other options do not align with the historical context and developments of Britain during this period. While Britain did engage in various foreign investments and strategies regarding its colonies, the purchase of majority shares in the Suez Canal Company stands out as a pivotal moment in reinforcing Britain's role in international commerce.