Astronomy current events question: Kuiper belt object colors

Astronomy 210L, Fall Semester 2010
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!)

Astronomy.com editors, "Kuiper Belt of Many Colors," November 1, 2010
http://astronomy.com/News-Observing/News/2010/11/Kuiper%20Belt%20of%20many%20colors.aspx

Scientists from NASA's Goddard Space Flight Center have proposed that the many different colors of Kuiper belt objects may come from:
(A) different layers exposed by the sun.
(B) tidal heating.
(C) sulfur-rich volcanoes and geysers.
(D) radioactive decays.
(E) simple organisms similar to algae or lichen.

Correct answer: (A)

Student responses
Sections 70178, 70186, 70200
(A) : 32 students
(B) : 3 students
(C) : 1 student
(D) : 3 students
(E) : 5 students