Classify the following costs as product or period. if product, further classify as direct or indirect.

a. electricity used to for lighting in production area. (Product or period, and direct or indirect)

b. wages of public relations personnel. (Product or period, and direct or indirect)

c. cost of compressor units used in producing air conditioners. (Product or period, and direct or indirect)

d. shipping charges for car bolts shipped to Ford factory. (Product or period, and direct or indirect)

e. uncut sheet metal used to make oven sides and doors. (Product or period, and direct or indirect)

f. salary of the CFO of the manufacturing company. (Product or period, and direct or indirect)