Astronomy current events question: erosion-exposed ice on Mars

Astronomy 210L, spring semester 2018
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!)

Guy Webster, Jennifer LaVista, Laurie Cantillo, and Dwayne Brown, "Steep Slopes on Mars Reveal Structure of Buried Ice" (January 11, 2018)
nasa.gov/feature/jpl/steep-slopes-on-mars-reveal-structure-of-buried-ice

NASA's Mars Reconnaissance Orbiter detected thick deposits of martian ice that were exposed by:
(A) sandstorms.
(B) marsquakes.
(C) recent solar flares.
(D) geysers.
(E) erosion.

Correct answer: (E)

Student responses
Section 30680
(A) : 2 students
(B) : 3 students
(C) : 5 students
(D) : 4 students
(E) : 11 students