The emf produced by an ac generator is given by $=$ NBA $sint.$ In SI units, what is the value of $$ for a frequency of $60\mathrm{.}0$ Hz $?$

$60\mathrm{.}0$ Hz

$120ra\frac{d}{s}$

$2\mathrm{.}00ra\frac{d}{s}$

$377ra\frac{d}{s}$

$377$ Hz