Astronomy current events question: planet formation stopped by active black holes

Astronomy 210L, fall semester 2014
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!)

Dennis O’Shea, "Big Black Holes Can Block New Stars," (October 21, 2014)
http://releases.jhu.edu/2014/10/21/starmaking-shutdown/

Johns Hopkins researchers propose particles ejected after nearly falling into massive black holes __________ in old galaxies.
(A) cause the collapse of all matter.
(B) distort space-time.
(C) are energy sources.
(D) produce dark matter.
(E) block new star formation.

Correct answer: (E)

Student responses
Sections 70178, 70186
(A) : 1 student
(B) : 1 student
(C) : 4 students
(D) : 4 students
(E) : 25 students