Final answer:
The most suitable cost driver for heating costs is c) floor space, as it has a direct impact on the amount of heating required for a facility.
Step-by-step explanation:
The question regards the identification of a suitable cost driver for heating costs at a facility level. The correct answer is (c) floor space. Cost drivers are factors that cause costs to change and in the context of heating, the amount of floor space has a direct relationship with heating costs.
Larger spaces generally require more heating, thereby implying higher heating costs compared to smaller spaces. Unlike machine hours, direct materials, and direct labor costs, which have varying impacts depending on the production process, floor space consistently influences the heating costs for a facility.