A company incurs janitorial cost of $120,000 per year which is shared by three departments. Manufacturing occupies 10,000 square feet and has 160 employees. Sales & Marketing occupies 6,000 square feet and has 90 employees. Administration occupies 9,000 square feet and has 50 employees. If janitorial cost is allocated based on square footage, the amount allocated to manufacturing is:

a. $72,000

b. $64,000

c. $48,000

d. $36,000