Astronomy current events question: oldest stars in Orion and NGC 2024 clusters

Astronomy 210L, spring 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, Janet Anderson, and Megan Watzke, "NASA's Chandra Observatory Delivers New Insight into Formation of Star Clusters," May 7, 2014
http://www.nasa.gov/press/2014/may/nasas-chandra-observatory-delivers-new-insight-into-formation-of-star-clusters/

Observations that outermost stars are oldest in the Orion and NGC 2024 clusters indicate that these clusters:
(A) are older than the known age of the universe.
(B) did not originally form in the Milky Way.
(C) have formed black holes.
(D) do not start forming in the middle.
(E) may not have Earth-like planets.

Correct answer: (D)

Student responses
Section 30682
(A) : 1 student
(B) : 1 student
(C) : 1 student
(D) : 18 students
(E) : 0 students