Answer:
The luminosity of both the stars is same star A is closer to the planet Earth as compared to star B.
Explanation:
From the mentioned case we can infer that the most accurate relation between the stars and the astronomer on earth observing for over a period is that the luminosity of the stars is same.
The more drawn out the pulsation time frame, the more brilliant the star. The period-luminosity connection for old style Cepheid was found in 1908 by Henrietta Swan Leavitt in an examination of thousands of different stars in the Magellanic Clouds.
The answer would be the cracking of rock caused by the freezing and thawing of water.
Just took the test and figured out the answer was A. Hoped I helped you and everyone else reading this.