Which of the following is an example of an indirect cost?

a. Security guard hourly wages for a plant that produces multiple objects: product B is the cost object

b. Insurance policy for a plant that produces multiple products- the plant is the cost object

c. rent costs for a plant that produces multiple products- the plant is the cost object

d. materials used in the production of product A- product a is the cost object

Please ANSWER WITHIN ONE HOUR! Thank you!