Astronomy current events question: Pluto moon hazards

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!)

Kelly Beatty, "A Problem with Pluto's Moons," October 17, 2012
http://www.skyandtelescope.com/news/home/The-Problem-with-Plutos-Moons-174686031.html

Pluto's newly discovered moons P4 and P5 could present a danger for NASA's New Horizon's spacecraft when it visits Pluto in 2015 because they may:
(A) themselves be orbited by smaller moonlets.
(B) suddenly collide into Pluto without warning.
(C) not be reflective enough to be seen.
(D) contain highly radioactive materials.
(E) be sources of dangerous high-speed debris.

Correct answer: (E)

Student responses
Sections 70178, 70186, 70200
(A) : 7 students
(B) : 2 students
(C) : 4 students
(D) : 0 students
(E) : 46 students