3. According to the article, why did Europeans so quickly accept that the sun did move and change? A. Europeans had already been questioning the accuracy of their religious beliefs long before scientists began observing sunspots.

B. Scientists published a significant amount of work on their findings about sunspots, which helped to convince the public.

C. The religious leaders at the time were very supportive of scientific observations about sunspots.

D. There had been so many sightings of sunspots all in the same time period, which proved that scientists were all observing the same thing.

there are no correct statementd on the list of choices you provided.

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.