Astronomy current events question: pre-Chicxulub impact event

Astronomy 210L, Fall 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, "The Dinosaurs Got a Warning Shot," August 31, 2010
http://www.skyandtelescope.com/news/101880488.html

__________ obtained by Scottish scientists buried in sedimentary layers in a recently-discovered impact crater indicate that life may have recovered quickly afterwards, until the later Chicxulub impact that killed the dinosaurs.
(A) Alien spores.
(B) Iridium samples.
(C) Small primitive mammal fossils.
(D) Lack of dinosaur fossils.
(E) Plant material.

Correct answer: (E)

Student responses
Sections 70178, 70186, 70200
(A) : 1 student
(B) : 3 students
(C) : 9 students
(D) : 4 students
(E) : 46 students