A geologist studies the earth's history.
The Salt Strike was the most aggressive revolt of the Indian National Congress. The correct option among all the options that are given in the question is the first option. This was actually a civil disobedience movement in a non violent matter. This is also an important movement in the history of India.
The answer is - Sunspots.
Sunspots are dark in appearance, but only on a visible light, and this is due to the fact that they are much cooler than the surrounding areas, but that doesn't mean by any means that the sunspots are cool, on contrary, they are very hot too. Sunspots actually are storms that appear in the lower atmosphere of the sun.
