Astronomy current events question: Earths around white dwarfs?

Astronomy 210L, Spring Semester 2011
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!)

Astronomy.com editors, "White Dwarfs Could Be Fertile Ground for Other Earths," March 31, 2011
http://astronomy.com/en/News-Observing/News/2011/03/White%20dwarfs%20could%20be%20fertile%20ground%20for%20other%20earths.aspx

Compared to other exoplanets, potentially habitable planets eclipsing white dwarfs could be observed using Earth-based telescopes because these planets would be:
(A) tidally locked.
(B) orbiting very close.
(C) much larger in size.
(D) much more Earth-like.
(E) near their final stage of life.

Correct answer: (B)

Student responses
Sections 30678, 30679, 30680
(A) : 5 students
(B) : 29 students
(C) : 5 students
(D) : 5 students
(E) : 6 students