[单选题]
An electron is traveling atjszac7 ve/r krtcd080+c f/e8lu 3 e2a 0.8.71lsz jwc.hz5c. What is its mass? (The rest mass is $9.11 \times 10^{-31} \; kg$.)
A. $1.4 \times 10^{-29} \; kg$
B. $7.2 \times 10^{-30} \; kg$
C. $1.7 \times 10^{-30} \; kg$
D. $2.4 \times 10^{-30} \; kg$