Astronomy current events question: Large Magellanic Cloud dark matter

Astronomy 210L, fall semester 2012
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!)

David A. Aguilar and Christine Pulliam, "Galactic Thief: 'I Would Have Gotten Away With It, If It Weren't for Those Meddling Astronomers,'" October 29, 2012
http://www.cfa.harvard.edu/news/2012/pr201230.html

According to computer simulations, dark matter MACHOs (massive halo compact objects) in the Large Magellanic Cloud could be observed by "microlensing," when these objects:
(A) convert infrared into visible light.
(B) make ripples in the Milky Way disk.
(C) trigger new star formation.
(D) deflect star trajectories.
(E) pass in front of background stars.

Correct answer: (E)

Student responses
Sections 70178, 70186, 70200
(A) : 7 students
(B) : 1 student
(C) : 4 students
(D) : 2 students
(E) : 9 students