Astronomy current events question: arcuate striations on Mars

Astronomy 210L, spring semester 2017
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!)

Thomas Deane, "Researchers Pinpoint Watery Past on Mars" (February 15, 2017)
jpl.nasa.gov/spaceimages/details.php?id=PIA20521

Comparison of "arcuate striations" in the Namib Desert on Earth with similar features on Mars observed by NASA's Mars Reconnaissance Orbiter indicate that both may be caused by repeated:
(A) ocean waves.
(B) dry ice snowfalls.
(C) magnetic pole fluctuations.
(D) dust storms.
(E) groundwater flooding.

Correct answer: (E)

Student responses
Sections 30679, 30680
(A) : 7 students
(B) : 1 student
(C) : 3 students
(D) : 6 students
(E) : 14 students