If an Astronomer Wanted to Find Some Relatively Complex Molecules

If an astronomer wanted to find some relatively complex molecules in space, what technique should she use?

A) point a gamma-ray telescope toward the center of the Milky Way Galaxy
B) take a spectrum of the visible light coming from our own Sun
C) point a radio telescope into regions in the galaxy where there is a lot of dust
D) use an ultra-violet telescope above the Earth's atmosphere to find highly ionized atoms
E) use the Hubble Space Telescope to take many visible-light images of faint nebulae