constant change of refractive index of the medium between the stars and the Earth because of temperature variation

frequent and periodic fluctuation of temperature of the surface

great distance of stars from the Earth

rise and fall of gaseous ball of fire inside the stars

Both A and R are individually true and R is the correct explanation of A

Both A and R are individually true but R is not the correct explanation of A

A is true but R is false

A is false but R is true

Krishna and Kaveri

Godavari and Krishna

Ganga and Mahanadi

Mahanadi and Godavari

2 million years ago

2 billion years ago

5 million years ago

5 billion years ago

Angola

Argentina

Sudan

Uruguay