Final answer:
The most likely reason Great Britain transferred ownership of Florida back to Spain following the American Revolution was inability to maintain control due to military and financial constraints.
Step-by-step explanation:
The most likely reason Great Britain transferred ownership of Florida back to Spain following the American Revolution was b) Inability to maintain control due to military and financial constraints.
After losing the thirteen colonies and the land between the Appalachians and the Mississippi, Britain returned Florida to Spain. Facing threats on all its borders and with limited resources, Great Britain could not effectively control the territory. This led to the decision to transfer ownership back to Spain.