In June, an investor finds out that in September she will receive $$10$ million to invest in three month maturity securities$.$ In June, the $91-$day Treasury bill rate is $5\mathrm{.}50$ per cent. What is the investor's profit $($loss$)$ if the $91-$day rate falls to $5\mathrm{.}20$ per cent in September?A$.$ The investor loses $$30000$ because of the $30$ basis point decline in interest rates.B$.$ The investor gains $$30000$ because of the $30$ basis point decline in interest rates.C$.$ The investor gains $$7583$ because of the $30$ basis point decline in interest rates.D$.$ The investor loses $$7583$ because of the $30$ basis point decline in interest rates.