Which statement is true?

A The pay yourself first budgeting method requires you to pay all outstanding bills before determining whether excess funds are available for savings.

B The surplus cash flow method differs from the envelope method of budgeting because it sets no limits on individual expense categories.

C The envelope method of budgeting relies on the use of cash only for certain types of expenses.

D Individuals tend to be overly optimistic in their budget forecasts primarily because they underestimate their income and overestimate their expenses.