The parallax method of measuring star distances gives most accurate results when the gap between two observations of a star is about six months. Which of these statements best explains why a gap between observations affects the accuracy of the star distance?

It allows the star to complete its life cycle and evolve from one form to another.

It ensures that measurements are taken from two points which are very far apart.

Question

The parallax method of measuring star distances gives most accurate results when the gap between two observations of a star is about six months. Which of these statements best explains why a gap between observations affects the accuracy of the star distance? 

 It allows the star to complete its life cycle and evolve from one form to another. 

 It ensures that measurements are taken from two points which are very far apart.