Astronomy current events question: "quasi-satellite" Plutino 15810

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!)

Camille Carlisle, "Pluto's Fake Moon," September 24, 2012
http://www.skyandtelescope.com/community/skyblog/newsblog/Plutos-Fake-Moon-170998771.html

Astronomers at the Universidad Complutense de Madrid have suggested that Plutino 15810 is a "quasi-satellite" of Pluto because it:
(A) closely leads or lags behind Pluto as they both orbit the sun.
(B) is too small to be considered a moon.
(C) passes back-and-forth between Pluto and its moon, Charon.
(D) is a fragment from a large impact on Pluto.
(E) does not have the same chemical composition as Pluto.

Correct answer: (A)

Student responses
Sections 70178, 70186, 70200
(A) : 20 students
(B) : 1 student
(C) : 4 students
(D) : 1 student
(E) : 0 students