Astronomy current events question: watery comet nucleus

Astronomy 210L, Spring Semester 2011
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, "Two Dying Stars Reborn as One," April 6, 2011
http://astronomy.com/News-Observing/News/2011/04/Frozen%20comet%20had%20a%20watery%20past%20University%20of%20Arizona%20scientists%20find.aspx

__________ found in sample from comet 81P/Wild 2 may be evidence of liquid water in a comet.
(A) Dry ice.
(B) Water-soluble minerals.
(C) Trapped air bubbles.
(D) Radioactive particles.
(E) Primitive algae-like fossils.

Correct answer: (B)

Student responses
Sections 30678, 30679, 30680
(A) : 11 students
(B) : 28 students
(C) : 2 students
(D) : 0 students
(E) : 8 students