Astronomy current events question: Mars river delta

Astronomy 210L, fall semester 2011
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!)

European Space Agency press release, "Rare Martian Lake Delta Spotted by Mars Express," September 2, 2011
http://www.esa.int/esaCP/SEMM71VTTRG_index_0.html

The European Space Agency Mars Express spacecraft observed __________ in Eberswalde crater on Mars, evidence that it may have once been a lake.
(A) a river delta.
(B) fluctuating magnetic fields.
(C) sand dunes.
(D) fossilized algae beds.
(E) shifting rocks and boulders.

Correct answer: (A)

Student responses
Sections 70178, 70186, 70200
(A) : 17 students
(B) : 3 students
(C) : 1 student
(D) : 0 students
(E) : 2 students