According to the Special Theory of Relativity,if a 30-Year Old

Multiple Choice

According to the special theory of relativity,if a 30-year old astronaut sent on a space mission is accelerated to speeds close to that of light,and then returns to Earth after 20 years as measured on Earth,what would be his biological age upon returning?

A) less than 50 years
B) 50 years
C) more than 50 years
D) exactly 100 years