Astronomy current events question: earliest detection of primordial hydrogen

Astronomy 210L, spring semester 2018
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!)

Jennifer Chu, "Astronomers Detect Earliest Evidence Yet of Hydrogen in the Universe" (February 28, 2018)
news.mit.edu/2018/astronomers-detect-earliest-evidence-yet-hydrogen-universe-0228

Primordial hydrogen absorbing light from the universe's first stars was recently detected using:
(A) adaptive optics.
(B) infrared interferometers.
(C) underground neutrino detectors.
(D) radio telescopes.
(E) particle accelerators.

Correct answer: (D)

Student responses
Sections 30679, 30680
(A) : 3 students
(B) : 11 students
(C) : 0 students
(D) : 22 students
(E) : 1 student