Astronomy current events question: visible light fluctuations from black hole V404 Cygni

Astronomy 210L, spring semester 2016
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!)

Jessica Hales, "'Seeing' Black Holes with Home-Use Telescopes" (January 7, 2016)
kyoto-u.ac.jp/en/research/research_results/2015/160107_1.html

Visible light fluctuations triggered by __________ can be observed from black hole V404 Cygni.
(A) neutrino bombardment.
(B) companion stars.
(C) infalling material.
(D) antimatter.
(E) gravity waves.

Correct answer: (C)

Student responses
Sections 30678, 30679, 30680
(A) : 3 students
(B) : 14 students
(C) : 15 students
(D) : 4 students
(E) : 11 students