a Everything Looks Like a Nail, Inc. is a manufacturing company that produces hammers. The company faces various fixed and variable costs in the short run. Determine which of Everything Looks Like a Nail's costs are fixed costs and which are variable costs. Assume the company cannot easily adjust the amount of capital that it uses and that salaries are negotiated only once per year.

a$.$ Postage and packaging costs:

b$.$ Lease on building:

c$.$ Cost of wood used in manufacturing:

d$.$ Industrial equipment costs:

e$.$ Interest on current debt: