[单选题]
What is the momentump1 gi .+yysj*/j -z7qw1tfl xopf+ 8-t+c7kp2j(dsrsb/k fg w in $kg \cdot m/s$ 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. $3.8 \times 10^{-19} \; kg \cdot m/s$
