Answer:
D. $1 comma 000 billion increase
Step-by-step explanation:
The reserve requirement ratio determines the total amount of checkable deposits a bank must keep.
In this case the reserve ratio it's 5%, which means that the total amount of deposits cannot exceed an amount equal to 20 times its reserves.
If the reserves increase by $50 billion then $50/0,05 = 1.000 billion increase.