Astronomy current events question: white dwarf dust disks

Astronomy 210L, spring 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!)

Jason Major, "Wreckage Around Nearby Stars Hints at Our Planet's Fate," May 3, 2012
http://www.msnbc.msn.com/id/47289413/ns/technology_and_science-space/#.T7E9rJ9YvXI

Researchers from the Royal Astronomical Society have observed four nearby white dwarf stars surrounded by disks of materials that could be:
(A) small asteroid belts.
(B) clouds of warm comets.
(C) the start of planetary formation.
(D) jovian planet rings.
(E) shattered remnants of terrestrial planets.

Correct answer: (E)

Student responses
Section 30682
(A) : 3 students
(B) : 0 students
(C) : 0 students
(D) : 0 students
(E) : 14 students