[单选题]
A spaceship takes a nonstop journh5 nf7yi :weapd. z);rey to a planet and retv, )tduyr.d;/dxr ix9;5re saurns in 10 hours according to a clock on the spaceship. If the speed of the spaceship is 0.80c, how mdu itd ,rx/ds;;yr.x )aev59ruch time has elapsed on the Earth?
A. $3.2 \; h$
B. $7.0 \; h$
C. $15 \; h$
D. $17 \; h$
