What main challenge does zero-based budgeting address?

Zero-based budgeting primarily addresses the challenge of eliminating unnecessary expenses by requiring all expenses to be justifiable for each new period, starting from a "zero base." This approach ensures that every department or project must justify its budget from scratch rather than taking the previous year's budget and adjusting it. As a result, organizations can closely scrutinize and prioritize all expenditures, thus identifying and cutting out costs that do not align with their current goals or operational needs. By emphasizing justification for every expense, zero-based budgeting promotes a more efficient allocation of resources, thus combating wasteful spending.

The other choices may relate to budgeting practices but do not encapsulate the central tenet of zero-based budgeting as effectively. For instance, justifying current spending patterns may involve evaluating previous budgets without an emphasis on starting from zero, while tracking variable costs and projecting long-term financial growth touch on different aspects of financial management that do not align with the core goals of zero-based budgeting.