Suppose the Burlington Donor Clinic of Canadian Blood Services has identified an individual blood drive as its cost object. It has established the following cost pools in developing an activity-based costing system:

Non-medical personnel costs. Salaries and wages of the office staff who organize blood drives and keep donor records.

Medical personnel costs. Salaries and wages of doctors and nurses who staff a blood drive.

Medical supplies. Cost of needles, bandages, and containers for donated blood.

Non-medical supplies. Costs of refreshments for blood donors and recordkeeping supplies.

Blood drives typically require 5 to 7 beds for blood donors. Each donation requires one container (in the medical supplies cost pool), one needle, and one set of bandages. Canadian Blood Services normally receives donated space from a community organization (such as a university or company) for each blood drive. Non-medical personnel costs would be most appropriately allocated using:

a. Number of blood drives organized

b. Number of blood donors

c. Hours available for blood donations

d. Dollar value of blood donated