A bank has an interest rate spread of $150$ basis points on $$30$ million in earning assets funded by interest$-$bearing liabilities. However, the interest rate on its assets is fixed and the interest rate on its liabilities is variable. If all interest rates go $($down$)50$ basis points, the bank's new pretax net interest income will be $\_\_\_\_\_\_\_\_\_\_.$

A$.$ $$600,000$

B$.$ $$450,000$

C$.$ $$300,000$

D$.$ $$250,000$

E$.$ $$175,000$