At the end of the previous fiscal year, a country had an outstanding national debt of £850 billion£850\text{ billion}£850 billion. For the upcoming fiscal year, the government has proposed a planned expenditure of £145 billion£145\text{ billion}£145 billion against a projected tax revenue of £125 billion£125\text{ billion}£125 billion.
All other things being equal, which one of the following is most likely to enable the government to complete its planned expenditure and reduce its national debt?
Increasing its planned borrowing by more than £20 billion£20\text{ billion}£20 billion.
Increasing its projected tax revenue by more than £20 billion£20\text{ billion}£20 billion.
Increasing its projected tax revenue by £20 billion£20\text{ billion}£20 billion and reducing planned borrowing by £20 billion£20\text{ billion}£20 billion.
Increasing both its projected tax revenue and planned borrowing by £20 billion£20\text{ billion}£20 billion.
