[单选题]
A spaceship takes a nonstop jb- wj /yok/ns3r3(frfd3xx 5bourney to a planet and req0lwe /ry e5mo28x874c aluy mturns in 10 hours according to a8lul2ar8 w5c/x e4em yo m0yq7 clock on the spaceship. If the speed of the spaceship is 0.80c, how much time has elapsed on the Earth?
A. $3.2 \; h$
B. $7.0 \; h$
C. $15 \; h$
D. $17 \; h$
