$17.$ A hedge fund currently invests in $$100$ million of mortgage$-$backed se$-$ curities $($MBS$)$ that have a duration of $13\mathrm{.}5$ and convexity of $-500($neg$-$ ative five hundred$).$ Which of the following is closest to how much money the fund would gain or lose if interest rates decreased by $1\%,$ using the duration$+$convexity approximation?

$($a$)$ Gain $$11$ million $($b$)$ Gain $$12$ million $($c$)$ Lose $$11$ million

$($d$)$ Lose $$12$ million $($e$)$ None of the above