[单选题]
How fast would a rocket ship have to move to contra8- d*aua,:3qg9 zeytwzqy 3jyct to half of its proper leng,qa :y9g83 a uyj*wzztdq-3ye 4yqm0k 3fxxzja 3w 9-ed8zk2lth (axzfd-2 mlky843xq 0ez k jw3a9s observed by a stationary object)?
A. $0.50 \; c$
B. $0.65 \; c$
C. $0.78 \; c$
D. $0.87 \; c$