[单选题]
Two spaceships are trakv3-p3w pf jx) jlo 73kum0jv8veling through space at 0.60 c relati7e0wav -7kduzve to the Earth. If the ships are headed directly toward each other, what is their approach kz wvadu7-e07 velocity, as measured by a person on either craft?
A. $1.2 \; c$
B. $c$
C. $0.60 \; c$
D. none of the given answers
