Indicate whether each statement is true or false.

a) Sunk costs are past costs that have already been incurred and they are irrelevant in decision making. (.)

b) Information that is useful in decision making must be relevant, accurate and timely. (.)

c) In many cases, fixed costs are avoidable. (.)

d) When only one limited resource is present, a company should focus on products that have the greatest amount of contribution margin per unit of scarce resource. (.)

e) Perfection standards assume that production takes place in the ideal world. (.)

f) The differences between standard costs and the actual costs incurred are recorded in variance accounts. (.)

g) A standard cost for each product cost category (materials, labor, and overhead) is calculated on a per-unit basis. (.)

please solve all with why