Which of the following statements is true regarding investing in manufacturing environments using automated systems?

a$.$ To decide whether to invest or not in an automated system can be done by comparing the net present value of the old project with the new one.

b$.$ While assessing the actual cost of an automated system, focus should not only be given to direct costs, but also to the peripheral costs, which can be substantial.

c$.$ For an automated system, the direct costs of acquisition represent virtually the entire investment.

d$.$ Estimates of operating cash flows from investments in automated systems typically rely on directly identifiable tangible benefits.