Astronomy current events question: brightness of supernova PS1-10afx

Astronomy 210L, spring 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!)

Shannon Hall, "Mysteriously Bright Supernova Explained," April 24, 2014
http://www.skyandtelescope.com/astronomy-news/stellar-science/mysteriously-bright-supernova-explained/

University of Tokyo astronomers propose that the extreme brightness of supernova PS1-10afx may have been due to a nearby galaxy:
(A) refocusing its light with gravity.
(B) adding dark energy.
(C) feeding it hydrogen.
(D) imploding, then exploding.
(E) triggering more supernovae.

Correct answer: (A)

Student responses
Sections 30678, 30679, 30680
(A) : 16 students
(B) : 3 students
(C) : 10 students
(D) : 6 students
(E) : 6 students