Astronomy current events question: formation of Mars' early atmosphere?

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, "Carbon's Role in Atmosphere Formation," April 8, 2013
http://news.brown.edu/pressreleases/2013/04/magma

Researchers investigated how magma in the moon and early Mars may have trapped and released atmospheric carbon by:
(A) analyzing sunlight reflected by the moon and Mars.
(B) using rovers on the moon and on Mars to drill into rocks.
(C) melting similar Earth rocks.
(D) creating lunar and Martian minerals from scratch.
(E) detecting fossil bacteria.

Correct answer: (C)

Student responses
Sections 30678, 30679, 30680
(A) : 7 students
(B) : 18 students
(C) : 19 students
(D) : 2 students
(E) : 5 students