Solve the Problem $t$ Seconds Is Given By $s(t)=-16 t^{2}$ , Where Negative Distance (Or Velocity) Indicates Downward Motion

Solve the problem.
-When an object is dropped straight down, the distance in feet that it falls in $t$ seconds is given by $s(t) =-16 t^{2}$ , where negative distance (or velocity) indicates downward motion. Find the velocity and acceleration at $\mathrm{t}=8$ .

A) Velocity $=-32 \mathrm{ft} / \mathrm{sec}$ ; acceleration $=0 \mathrm{ft} / \mathrm{sec}^{2}$
B) Velocity $=-256 \mathrm{ft} / \mathrm{sec}$ ; acceleration $=-32 \mathrm{ft} / \mathrm{sec}^{2}$
C) Velocity $=-32 \mathrm{ft} / \mathrm{sec}$ ; acceleration $=-256 \mathrm{ft} / \mathrm{sec}^{2}$
D) Velocity $=-256 \mathrm{ft} / \mathrm{sec}$ ; acceleration $=0 \mathrm{ft} / \mathrm{sec}^{2}$