The joint stock company facilitated colonial expansion primarily by spreading risk among many investors and expanding the amount of capital available with which to develop colonies. This financial model allowed multiple investors to pool their resources, thereby minimizing individual risk while increasing the capital available for large-scale colonial ventures. It enabled the funding of expeditions, trade missions, and the establishment of settlements, leading to more extensive and sustained colonial endeavors.
While the other options mentioned may reflect some truths about the broader context of colonialism, they do not directly address the primary role of joint stock companies in facilitating colonial expansion.