Astronomy current events question: M81 halo

Astronomy 210L, Spring Semester 2010
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!)

Kelly Beatty, "A New Take on M81's Halo," May 3, 2010
http://www.skyandtelescope.com/news/92734814.html

Researchers using data from Japan's Subaru telescope have determined that the halo of spiral galaxy M81 __________ than the halo of the Milky Way.
(A) is mainly composed of antimatter.
(B) contains much more dark matter.
(C) is more abundant in heavy elements.
(D) is much smaller.
(E) has a greater redshift.

Correct answer: (B)

Student responses
Section 30682
(A) : 0 students
(B) : 4 students
(C) : 5 students
(D) : 0 students
(E) : 1 student