Mark has a certain amount budgeted for dining out each month. Last month, the difference between the amount he budgeted and the amount he actually spent on dining out was less than -20 dollars. Which of the following best describes this situation?
A.
Mark is under his budget by less than 20 dollars.

B.
Mark is under his budget by more than 20 dollars.

C.
Mark is over his budget by less than 20 dollars.

D.
Mark is over his budget by more than 20 dollars.