Which of These Features Appears in the Spectrum of the Solar

Multiple Choice

Which of these features appears in the spectrum of the solar corona and indicates very high gas temperatures?

A) intense emission lines from highly ionized atoms, such as iron
B) bright emission from the hydrogen Balmer line, H _$\alpha$ , at the red end of the spectrum
C) intense continuous emission in the infrared part of the spectrum
D) dark absorption lines from hydrogen, calcium, and iron on a continuous bright spectrum