Astronomy current events question: measuring extrasolar planet sizes

Astronomy 210L, fall semester 2012
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!)

ESA Media Relations Office, "ESA Science Programme's New Small Satellite Will Study Super-Earths," October 19, 2012
http://www.esa.int/esaCP/SEMXFG4S18H_index_0.html

The European Space Agency is planning to launch the CHEOPS (Characterising ExOPlanets Satellite) spacecraft in 2017 to measure the radius of already discovered extrasolar planets by observing how:
(A) slowly they rotate.
(B) they transit in front of their stars.
(C) many moons (if any) orbit them.
(D) much light they reflect from their stars.
(E) they wobble their stars.

Correct answer: (B)

Student responses
Sections 70178, 70186, 70200
(A) : 0 students
(B) : 25 students
(C) : 2 students
(D) : 2 students
(E) : 3 students