Astronomy quiz question: northwest setting Sun

Astronomy 210 Quiz 1, Fall Semester 2008
Cuesta College, San Luis Obispo, CA

[4.0 points.] Which month would the Sun set in the northwest horizon, as seen by an observer in San Luis Obispo, CA?
(A) March or September.
(B) June.
(C) December.
(D) (None of the above choices, as it is not possible for the sun to set in the northwest horizon in San Luis Obispo, CA.)

Correct answer: (B)

In June (summer solstice), the Sun will rise northeast, pass the meridian very close to the zenith, and then set northwest. In March or September (vernal/autumnal equinoxes), the Sun will rise directly from the east and set in the west, while in December (winter solstice) the Sun will rise in the southeast, pass the meridian closer down towards the horizon, and eventually set southwest.

Student responses
Section 70158
(A) : 24 students
(B) : 27 students
(C) : 17 students
(D) : 7 students

"Difficulty level": 39%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.43