Because costs will be incurred as a result of unexpected events throughout a year,

a.it is impossible to budget for them since we do not know when they will occur.

b.we can budget for the fact that they will occur, even if we cannot predict when they will occur.

c.we will always be unprepared for them, simply because they are unexpected.

d.it is important to have several credit cards with unused balances in order to best deal with these costs