Each Atom in a Sample of Lithium $\mathrm{Z}=3$ , Atomic Mass

Each atom in a sample of lithium ( $\mathrm{Z}=3$ , atomic mass $6.941 \mathrm{u}$ ) has one electron removed. If a charge of magnitude $1.0 \mathrm{mC}$ was collected in this way, what is the mass of the lithium sample?

A) $0.031 \mu \mathrm{g}$
B) $0.010 \mu \mathrm{g}$
C) $0.072 \mu \mathrm{g}$
D) $0.024 \mu \mathrm{g}$