Assertion : Parallax method cannot be used for measuring distance of stars morer then 100 light year away.
Reason : Because parallax angle reduces so much that it cannot be measured accurately.

Options

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion
C. If assertion is true but reason is false.
D. If the assertion and reason both are false

Answer

A

Explanation

As the distance of star increases, the parallax angle decreases and great degree of accuracy is required for its measurement
So, the maximum distance of a star we can measure is limited to 100 light years.