Answer:
C. decreased by $40 billion
Explanation:
For computing the lending ability, first we have to determine the money multiplier which is shown below:
We know that
Money multiplier = 1 ÷ reserve ratio
= 1 ÷ 20%
= 5
So, the total cash would be
= $10 billion × $5
= $50 million
Now the lending ability would be
=$50 billion × (1 - 20%)
= $50 billion × 0.80
= $40 billion