Astronomy current events question: ridges on Mars

Astronomy 210L, spring semester 2013
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!)

Kevin Stacey, "Ridges on Mars Suggest Ancient Flowing Water," January 29, 2013
http://news.brown.edu/pressreleases/2013/01/marswater

According to Brown University researchers, __________ may be evidence of water that had once flowed beneath the surface of Mars.
(A) long collapsed tunnels and canals.
(B) networks of ridges in impact craters.
(C) mineral-rich spherules called "blueberries."
(D) underground pockets of dry ice.
(E) layers and layers of sedimentary rocks.

Correct answer: (B)

Student responses
Sections 30678, 30679, 30680
(A) : 6 students
(B) : 35 students
(C) : 5 students
(D) : 5 students
(E) : 5 students