Astronomy current events question: two new moons for Uranus?

Astronomy 210L, fall semester 2016
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!)

Ken Croswell, "Uranus Might Have Two Dark Moons We’ve Never Seen Before" (October 14, 2016)
newscientist.com/article/2109101-uranus-might-have-two-dark-moons-weve-never-seen-before/

Uranus may have two previously undiscovered moons, based on re-examination of images of __________ from NASA's Voyager 2 spacecraft.
(A) eclipse shadows.
(B) atmospheric eddies.
(C) colliding asteroids.
(D) intermittent reflections.
(E) wavy ring patterns.

Correct answer: (E)

Student responses
Sections 70178, 70186
(A) : 4 students
(B) : 1 student
(C) : 0 students
(D) : 2 students
(E) : 17 students