Astronomy current events question: volcanic interactions with Mar's oceans?

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!)

Robert Sanders, "Mars' Oceans Formed Early, Possibly Aided by Massive Volcanic Eruptions" (March 20, 2018)
eps.berkeley.edu/news/mars’-oceans-formed-early-possibly-aided-massive-volcanic-eruptions

Researchers propose that Mars' oceans formed much earlier and shallower than previously thought, due to:
(A) volcanic activity.
(B) comet bombardment.
(C) global cooling.
(D) perchlorate rains.
(E) global sandstorms.

Correct answer: (A)

Student responses
Sections 30679, 30680
(A) : 29 students
(B) : 6 students
(C) : 2 students
(D) : 1 student
(E) : 1 student