When a $0\mathrm{.}350-$kg object is attached to a vertical spring and lowered slowly the spring extends $12$ cm$.$ What is the spring constant of the spring?

Question $21$ options:

A$)$

$12\mathrm{.}5$ N$/$m

B$)$

$0\mathrm{.}102$ N$/$m

C$)$

$2\mathrm{.}1$ N$/$m

D$)$

$25\mathrm{.}6$ N$/$m

E$)$

$0\mathrm{.}610$ N$/$m