A researcher conducts an experiment using 10 loads of white shirts with similar stains. The loads are divided, and 5 of the loads are washed with name-brand detergent, while the other 5 are washed with store-brand detergent. Volunteers are asked to assess the cleanliness of the shirts. What are the experimental units in this setting? the types of detergent the 10 loads of shirts the volunteers who assess the stains the machines used to wash the shirts