[单选题]
What is the momentum 96 0-aa/zcjx ;dwy ycxzbexf mhv-:-/ in6lbr7 h9z2qlv : b+j :)zikovg $kg \cdot m/s$ of a proton when it is moving with a speed of 0.60c?
A. $1.2 \times 10^{-19} \; kg \cdot m/s$
B. $1.5 \times 10^{-19} \; kg \cdot m/s$
C. $3.0 \times 10^{-19} \; kg \cdot m/s$
D. $3.8 \times 10^{-19} \; kg \cdot m/s$