What Is the Best Way to Approach the Preparation of a Production

What is the best way to approach the preparation of a production budget?

A) include expenses that might occur when things go wrong
B) make the budget attractive by underestimating some expenses
C) protect yourself against cost overruns by overestimating all expenses by 10 percent
D) be realistic but add a contingency of at least 15 percent
E) leave blank any expenses likely to change before the production is completed