Answer:
A. Bulldozers
Explanation:
Factor markets refer to a place wherein factors of production such as labor, capital are sold.
Factor markets are also referred to as the markets for inputs. Various inputs that aid the production process are bought and sold in such markets.
In the given question, bulldozers constitutes machinery for lifting and disposing off sand and other construction material. It represents a machinery which aids in production and thus is bought and sold in the factor market.
