Evaluate the validity of each of the following prompts, and justify

1) ABC systems are generally more worthwhile when the organization's products are more heterogenous (i.e., use overhead resources differently) and when a higher proportion of costs are direct rather than indirect.

2) EBITDA is an effective financial metric for performance measurement in part because it creates incentives for managers to limit capital expenditures.

3) If sales volume exceeds that expected per the static budget, then sales activity variances will always be unfavorable both for variable costs and for fixed costs.

4) Managers should discontinue all unprofitable product lines.

5) The net book value of a piece of equipment is relevant financial information when considering whether to sell it.