In paragraph 3, the author mentions all of the following characteristics of the sun EXCEPT:
A.
The photosphere is the visible layer of the sun where energy escapes into space as sunlight.
B.
Nuclear fusion takes place in the sun's core and travels outwards through a number of different layers.
C.
The photosphere, which is 100 km thick, has a lower temperature than the sun's outer atmosphere.
D.
The sun has a magnetic core made of liquid iron that is kept in constant motion by the sun's rotation.