How Do Astronomers Learn What Elements Are Present in a Given

Multiple Choice

How do astronomers learn what elements are present in a given star?

A) look at what color light dominates its continuous spectrum
B) listen for coded signals in the radio waves it gives off in the FM band
C) look at the absorption lines in its spectrum
D) send spacecraft like Voyager to examine its make-up from close-up
E) compare visible-light photographs of the star (taken with large telescopes) to those of the Sun.