Astronomy current events question: gravitational lensing of distant galaxy

Astronomy 210L, fall semester 2014
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!)

J.D. Harrington, Donna Weaver, and Ray Villard, "Hubble Shows Farthest Lensing Galaxy Yields Clues to Early Universe," July 31, 2014
http://www.nasa.gov/press/2014/july/hubble-shows-farthest-lensing-galaxy-yields-clues-to-early-universe/

NASA's Hubble Space Telescope observed the most distant galaxy that uses __________ to magnify even more distant objects beyond it.
(A) gravitational forces.
(B) magnetic fields.
(C) lookback time.
(D) dark energy.
(E) Doppler redshifts.

Correct answer: (A)

Student responses
Sections 70178, 70186
(A) : 12 students
(B) : 12 students
(C) : 3 students
(D) : 5 students
(E) : 6 students