What Is Surprising About the Atmosphere of the Sun

What is surprising about the atmosphere of the Sun?

A) The pressure of the Sun's atmosphere, after dropping just above the photosphere, rises again to a value equivalent to that at the photosphere at the top of the chromosphere.
B) The density of the Sun's atmosphere, after falling rapidly above the photosphere, rises again significantly in the chromosphere.
C) The temperature of the Sun's atmosphere, after rising continuously from below the photosphere through the chromosphere, falls again suddenly in the corona.
D) The temperature of the Sun's atmosphere, after falling above the photosphere, rises again to reach very high values high in the atmosphere.