Answer:
C. about 25 years.
Explanation:
We have been given that two Jackie takes off on a round-trip to Vega, 25 light-years away. She travels at an average speed close to the speed of light, say, 0.9999c.
To find time it will take Jakie to reach Vega, we will divide the distance of Vega by Gwen's speed.
Therefore, it will take approximately 25 years for Jakie to reach Vega and option C is the correct choice.