If a dust grain has a density of 3 gm/cc, what is the typical mass of a dust grain?

[Weatherman]

a) 3.39x10^-4gms
b) 3.39x10^-2gms
c) 3.39x10^-1gms
d) 3.39x10^2gms
e) 3.39x10^4gms