Astronomy quiz question: largest star?

Astronomy 210 Quiz 5, spring semester 2018
Cuesta College, San Luis Obispo, CA

Which star is largest?
(A) A0 supergiant.
(B) B5 main sequence star.
(C) F0 main sequence star.
(D) K5 supergiant.
(E) (There is a tie.)

Correct answer (highlight to unhide): (D)

An H-R diagram is provided with this quiz.


These stars are plotted on an H-R diagram below. The K5 supergiant is largest, followed by the A0 supergiant, B5 main sequence star, and the F0 main sequence star is the smallest.


Section 30674
Exam code: quiz05NoPw
(A) : 1 student
(B) : 1 student
(C) : 0 students
(D) : 10 students
(E) : 7 students
(No response: 1 student)

Success level: 57% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.80