Astronomy current events question: "jellyfish" galaxy tail formation

Astronomy 210L, fall 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!)

Alessandra Potenza, "How the Tentacles of Jellyfish Galaxies Feed Supermassive Black Holes" (August 17, 2017)
theverge.com/2017/8/17/16154140/jellyfish-galaxies-space-supermassive-black-holes-gas

Observations of several "jellyfish" galaxies indicate that they may be feeding their central black holes with their own long tails of:
(A) ejected gas.
(B) antimatter.
(C) gravitational waves.
(D) magnetic field lines.
(E) dark matter.

Correct answer: (A)

Student responses
Sections 70178, 70186
(A) : 36 students
(B) : 5 students
(C) : 4 students
(D) : 1 student
(E) : 5 students