Answer: b. be in deficit by at least $50 billion.
Step-by-step explanation:
The Government budget had been balanced but it will now have to spend $50 billion more than it is making. This will mean that Government expenditure will rise by $50 billion over the tax revenue which will lead to a deficit of the same amount.
These are bonds however meaning that the Government would have to pay interest on the $50 billion. This will push the deficit owed to over $50 billion meaning that the Government would be in deficit of at least $50 billion.