A string with a mass per length of $2\mathrm{.}00$ g$/$m is stretched with a force of $120$ N between two points that are $0\mathrm{.}400$ m apart. The fundamental frequency of the stretched string is in tune with the fundamental frequency of an organ pipe filled with air and open at both ends. The speed of sound in air at $0$C is $331$ m$/$s$.$ What is the length of the organ pipe?

Multiple Choice

$54\mathrm{.}1$ cm

$59\mathrm{.}0$ cm

$61\mathrm{.}5$ cm

$63\mathrm{.}5$ cm

$66\mathrm{.}8$ cm