Astronomy current events question: Viking lander results

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, "Missing Piece Inspires New Look at Mars Puzzle," September 7, 2010
http://www.astronomy.com/asy/default.aspx?c=a&id=10194

Scientists recently proposed that the NASA Viking landers had detected organic compounds in martian soil, rather than from:
(A) self contamination.
(B) solar flares.
(C) cosmic rays.
(D) dry ice geysers.
(E) acid rain chemicals.

Correct answer: (A)

Student responses
Sections 70178, 70186, 70200
(A) : 46 students
(B) : 5 students
(C) : 3 students
(D) : 7 students
(E) : 3 students