Astronomy current events question: Scholz's star pass-by

Astronomy 210L, spring semester 2015
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!)

Leonor Sierra, "A Close Call of 0.8 Light Years," (February 16, 2015)
http://www.rochester.edu/newscenter/scholz-star/

WISE J072003.20-084651.2, or "Scholz’s star" passed through the outer edge of our solar system 70,000 years ago, based on:
(A) comet orbits.
(B) its speed and trajectory.
(C) ancient petroglyphs.
(D) solar flare anomalies.
(E) iridium-rich sediments.

Correct answer: (B)

Student responses
Sections 30678, 30679, 30680
(A) : 7 students
(B) : 34 students
(C) : 2 students
(D) : 9 students
(E) : 1 student