A $2\mathrm{.}00-kg$ body is attached to a spring of negligible mass and oscillates with a period of $1\mathrm{.}00$ s $.$ The force constant of the spring is

$0\mathrm{.}051$ N$/$m

$0\mathrm{.}500\frac{N}{m}$

$2\mathrm{.}00\frac{N}{m}$