[单选题]
The mass of an electron isz.v q2 8qymo.t9t/wz d/gab n8jdo c(6*lez/of4 bzwm19: vds $9.1 \times 10^{-31} \; kg$. How many electrons will make a mass of 1.0 kg?
A. $9.1 \times 10^{30}$
B. $1.1 \times 10^{30}$
C. $9.1 \times 10^{31}$
D. $1.1 \times 10^{31}$
