Answer:
The correct answer is option C, 13 billion
Step-by-step explanation:
Most of the scientists believe that the age of universe is approximately 13.77 billion years. The estimates age is based on the distances and radial velocities of other galaxies which are moving away from each other at a speed directly proportional to their distance. Basically the logic is to measure the time must that has elapsed between the Big Bang incidence and the present.