Concept:Factory overhead consists of indirect production costs that are not directly traceable to a specific product.
Explanation:Factory overhead includes costs like depreciation of plant and machinery, factory rent, utilities, and supervisor salaries.
These costs support production but cannot be classified as direct materials or direct labour.
Raw materials consumed is a direct material cost, so option A is not overhead.
Manufacturing wages are direct labour costs, so option B is not overhead.
Depreciation of plant and machinery is an indirect cost incurred in the factory, so it is a component of factory overhead.
Therefore, the correct option is D.
Answer:D. depreciation of plant and machinery