[单选题]
One 20-year-old twin arr/ edr (l-lycw93jb f x1e5;brother takes a sxbru,t,*09+pf f fdg tpace trip with a speed of 0.80c for 30 years according to 0b, f,xr 9tf+ ftgp*dua clock on the spaceship. Upon returning to the Earth, what is his own age and the age of the Earth-based twin brother?
