Answer :
I believe the answer is: A. human resources.
In current understanding, human resources could be divided into intellectual resources (such as creative thinking or long-term planning) and physical resources (that include manual labor such as operating machines or setting up roofs on a building)
In current understanding, human resources could be divided into intellectual resources (such as creative thinking or long-term planning) and physical resources (that include manual labor such as operating machines or setting up roofs on a building)