Which of the following represents a way of coping with uncertainty in a cash budget?

(a) always using the prior year's data for estimates of the future

(b) using scenario analysis, or "what if" approach, to analyze cash flows under a variety of circumstances

(c) careful estimation of cash budgets outputs

(d) developing a pro forma income statement to forecast sales and then express the various income statement items as percentage of projected sales

(Please explain answer)