Classify each of the following costs as Product (direct/indirect) or Period and Variable, Fixed or Mixed.

Costs	Product (Direct/Indirect) or Period	Variable/Fixed/Mixed
Wages of assembly-line workers
Depreciation of plant equipment
Glue and nails for production
Outbound delivery expense
Raw materials handling costs
Salary of marketing manager
Production run setup costs
Administrative office utilities
Electricity cost of retail stores
Research and development expense