Astronomy current events question: comet 67P/Churyumov-Gerasimenko color changes

Astronomy 210L, spring semester 2020
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!)

Gianrico Filacchione, Fabrizio Capaccioni, and Matt Taylor, "Rosetta and the Chameleon Comet" (February 5, 2020)
esa.int/Science_Exploration/Space_Science/Rosetta/Rosetta_and_the_chameleon_comet

The European Space Agency's Rosetta spacecraft images show how comet 67P/Churyumov-Gerasimenko changed __________ as it passed near the sun.
(A) colors.
(B) density.
(C) trajectory.
(D) solar flares.
(E) rotation rate.

Correct answer: (A)

Student responses
Sections 30679, 30680
(A) : 36 students
(B) : 1 student
(C) : 0 students
(D) : 1 student
(E) : 0 students