Where and by What Technique Was the Element Helium First

Multiple Choice

Where and by what technique was the element helium first discovered?

A) in radioactive rocks, by radioactive measurements of uranium deposits
B) on the Sun, from spectroscopy during a solar eclipse
C) in the laboratory, by examining the spectrum of heated chemicals in a flame
D) in the upper atmosphere of Earth, by studying the spectrum of the aurorae, or northern lights