Astronomy current events question: Mars' dark streak water content?

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!)

Guy Webster, Dwayne Brown, and Laurie Castillo, "Test for Damp Ground at Mars' Seasonal Streaks Finds None" (August 23, 2016)
jpl.nasa.gov/news/news.php?release=2016-215

Dark streaks on the surface of Mars do not contain much water, as determined by NASA's Mars Odyssey spacecraft's:
(A) analysis of laser pulses.
(B) infrared measurements from space.
(C) soil drilling samples.
(D) radar signals.
(E) photographs from different seasons.

Correct answer: (B)

Student responses
Sections 70178, 70186
(A) : 2 students
(B) : 14 students
(C) : 10 students
(D) : 0 students
(E) : 5 students