You launch a projectile horizontally from a building $30\mathrm{.}1$ m above the ground at another building $31\mathrm{.}5$ m away from the first building. The projectile strikes the second building $7\mathrm{.}6$ m above the ground. What was the projectile s launch speed? a$.25\mathrm{.}31$ m$/$s b$.31\mathrm{.}64$ m$/$s c$.14\mathrm{.}71$ m$/$s d$.12\mathrm{.}72$ m$/$s