The correct answer will be option the distance of the star from Sun using parallax method.
Explanation:
Parallax method or trigonometric parallax is a method of measuring the distance of nearby stars in space on the basis of displacement of stars against the background.
Since a student observes the position of the star in summer and then after 6 months in winter, star changes its position or displaces which can be measured by the student along with measuring parallax angle and drawing a baseline from the Sun as Earth revolves in orbit around the Sun. So by using the parallax method and the formula he can easily determine the distance from the Sun.
Thus, the distance of the star from Sun using the parallax method is the correct answer.
