$(3$ points$)$: A solid, conducting sphere of radius $6\mathrm{.}0$ cm is given some charge. The electric potential at the center of the solid sphere is equal to $+3\mathrm{.}0$ kV relative to infinity $($and infinity is where the potential is defined to be zero volts$).$ What is the total charge that was placed on the conductor?

$1$ nC

$5$ nC

$20$ nC

$100$ nC

$300$ nC

$900$ nC