INSIGHT UPSC QUIZ

ANS. (C) 
The outermost layer of the sun is the corona. Only visible during eclipses, it is a low density cloud of plasma with higher transparency than the inner layers. The white corona is a million times less bright than the inner layers of the sun, but is many times larger. A corona is a type of plasma “atmosphere” of the Sun or other celestial body, extending millions of kilometers into space, most easily seen during a total solar eclipse, but also observable in a coronagraph. The word “corona” itself derived from the Latin, meaning crown. The high temperature of the corona gives it unusual spectral features