Astronomy quiz question: Arcturus setting versus Spica setting

Astronomy 210 Quiz 1, fall semester 2013
Cuesta College, San Luis Obispo, CA

The diagram at right shows positions of constellations and stars near the horizon, as seen at 8:00 PM by an observer in San Luis Obispo, CA. Ignore daylight saving time. 
Assume you can see stars in daylight. Which star will set first?
(A) Arcturus.
(B) Spica.
(C) (There is a tie.)
(D) (Neither star will set, as they are circumpolar.)

Correct answer (highlight to unhide): (B)

Using a starwheel (planisphere), the sky as shown is 8:00 PM on April 10 (or some other start time/date can be selected). Spica will set first at 5:30 AM the next day (April 11), while Boötes will set later at 8:30 AM.

Section 70158
Exam code: quiz01S0u7
(A) : 4 students
(B) : 37 students
(C) : 2 students
(D) : 3 students

Success level: 80% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.42