Convert $3\mathrm{.}64{10}^{-7}$ grams to micrograms.

$3\mathrm{.}64{10}^{-1}g$

$3\mathrm{.}64{10}^{-13}g$

$3\mathrm{.}64{10}^{-4}g$

$3\mathrm{.}64{10}^{-10}g$