Astronomy current events question: Proxima Centauri's cold dust belt

Astronomy 210L, fall semester 2017
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!)

Guillem Anglada, Pedro J. Amado, Antxon Alberdi, Enrique Macias, Itziar de Gregorio-Monsalvo, and Richard Hook, "ALMA Discovers Cold Dust Around Nearest Star" (November 3, 2017)
eso.org/public/news/eso1735/

The Atacama Large Millimeter/submillimeter Array Observatory detected a dust belt surrounding the star Proxima Centauri, which may indicate the presence of:
(A) gravitational waves.
(B) cold dark matter.
(C) a white dwarf.
(D) multiple planets.
(E) artificial asteroids.

Correct answer: (D)

Student responses
Sections 70178, 70186
(A) : 1 student
(B) : 7 students
(C) : 2 students
(D) : 28 students
(E) : 4 students