Astronomy current events question: Very Large Telescope laser guide star

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!)

Domenico Bonaccini Calia, Wolfgang Hackenberg, and Richard Hook, "First Light of New Laser at Paranal" (May 8, 2015)
http://www.eso.org/public/usa/announcements/ann15034/

The European Southern Observatory's Very Large Telescope in Chile uses a laser while observing to:
(A) evaporate high-altitude clouds.
(B) subtract out light pollution.
(C) dust off its mirrors.
(D) measure atmospheric turbulence.
(E) determine target distances.

Correct answer: (D)

Student responses
Section 30680
(A) : 1 student
(B) : 0 students
(C) : 2 students
(D) : 11 students
(E) : 2 students