Astronomy current events question: Europa subsurface ocean oxygen?

Astronomy 210L, Fall Semester 2009
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, "Europa Ocean May Contain Enough
Oxygen to Support Life," October 9, 2009
http://www.astronomy.com/asy/default.aspx?c=a&id=8706

According to a University of Arizona researcher, what is the proposed source for oxygen that may be found in the subsurface oceans of Jupiter's moon, Europa?
(A) Charged particles impacting its icy surface.
(B) Water- and oxygen-rich asteroids.
(C) Open vents in the ice.
(D) Exotic chemical processes on the warm ocean floor.
(E) Photosynthesis.

Correct answer: (A)

Student responses
Sections 70178, 70186, 70200
(A) : 16 students
(B) : 7 students
(C) : 13 students
(D) : 18 students
(E) : 2 students