Astronomy current events question: binary system Kepler-47 exoplanets

Astronomy 210L, spring semester 2019
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!)

News release, "Astronomers Discover Third Planet in the Kepler-47 Circumbinary System" (April 16, 2019)
newscenter.sdsu.edu/sdsu_newscenter/news_story.aspx?sid=77597

The three circumbinary planets of the Kepler-47 system were discovered as they __________ their two host stars.
(A) collided with.
(B) broke away from.
(C) passed in front of.
(D) reflected light from.
(E) gravitationally pulled.

Correct answer: (C)

Student responses
Sections 30679, 30680
(A) : 1 student
(B) : 16 students
(C) : 27 students
(D) : 2 students
(E) : 3 students