When Preparing to Put Together a Budget to Determine How

When preparing to put together a budget to determine how much you need to earn to cover your living expenses, you should

A) include only your major expenses such as rent and car payments.
B) keep track of as many of your expenses as possible for 2 or 3 months.
C) save time by just estimating what you think you spend.
D) record in detail everything you spend for several months.