$(2$ points$)$ A steel ball is hung from a vertical ideal spring where it oscillates in simple harmonic motion with a period T$.$ At time $t=0s,$ the ball is at its maximum displacement, A $,$ from its equilibrium position. In terms of the period, at what time will the ball be at $y=0\mathrm{.}75A?$

A$.0\mathrm{.}33$ T $0\mathrm{.}75$ A

$($B$)0\mathrm{.}25$ T

C$.0\mathrm{.}15$ T

D$.0\mathrm{.}12$ T $.$