Astronomy current events question: early stages of Milky Way-like galaxies

Astronomy 210L, spring semester 2017
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

Tim Stephens, "Astronomers Observe Early Stages of Milky Way-like Galaxies in Distant Universe" (March 23, 2017)
mpifr-bonn.mpg.de/pressreleases/2017/4

The Atacama Large Millimeter Array (ALMA) in Chile observed early stages of Milky Way-like galaxies by measuring how their surrounding "super halo" of __________ absorbed light from their own quasars.
(A) distorted space-time.
(B) hydrogen gas.
(C) dark matter.
(D) globular clusters.
(E) antimatter.

Correct answer: (B)

Student responses
Sections 30679, 30680
(A) : 0 students
(B) : 16 students
(C) : 5 students
(D) : 8 students
(E) : 2 students