Astronomy final exam question: life on massive main sequence star exoplanets

Astronomy 210 Final Exam, Fall Semester 2008
Cuesta College, San Luis Obispo, CA

[4.0 points.] Why are planets that orbit massive main sequence stars not thought to be good candidates for life to exist?
(A) Massive main sequence stars are too luminous.
(B) Massive main sequence stars have short lifetimes.
(C) These planets would be geologically dead.
(D) These planets would be too large.

Section 70160
(A) : 1 students
(B) : 27 students
(C) : 2 students
(D) : 0 students

Correct answer: (B)

Massive star have main sequence lifetimes on order of millions of years (or even less), much less than how biological life arose from chemical evolution arose on Earth (on order of billions of years), with the caveat that this process would take the same amount of time elsewhere.

"Difficulty level": 91% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.25