Classify the following costs as unitrelated, batch-related, product-sustaining, or business-sustaining activity costs:

a. packing labor wages

b. materials-handling labor wages

c. part administrators salaries

d. plant management salaries

e. production scheduling staff salaries

f. cost of servicing production equipment, based on hours used

g. property taxes for a plant site

h. production expediters' salaries

i. insurance for plant facility

j. plant security

k. production workers' training

l. cost of electricity to run production equipment