Based on the historical context of James Oglethorpe's recruitment of the Highland Scots, the option that BEST indicates the reason for their recruitment is:
C. Based on the weapons in the image, the Highland Scots were used to defend the Georgia colony against the Spanish threat in Florida.
This aligns with the historical fact that Oglethorpe sought the Highland Scots for their military skills and experience, particularly to bolster defenses against potential Spanish attacks.