Astronomy current events question: binary system exoplanet

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!)

Michele Johnson, "NASA's Kepler Mission Discovers a World Orbiting Two Stars," September 15, 2011
http://www.nasa.gov/mission_pages/kepler/news/kepler-16b.html

Kepler-16b, a planet orbiting two stars, was discovered by NASA's Kepler spacecraft by observations of it __________ the stars it orbits.
(A) interfering with magnetic fields of.
(B) passing in front of.
(C) absorbing radio transmissions from.
(D) producing dark matter in.
(E) deflecting solar flares from.

Correct answer: (B)

Student responses
Sections 70178, 70186, 70200
(A) : 3 students
(B) : 22 students
(C) : 2 students
(D) : 0 students
(E) : 0 students