What is the altitude of the north celestial pole as seen from our latitude in Baltimore (39 °N)? (You may want to use the Rotating Sky Explorer to investigate this question. If you're still not sure, add a star to the celestial sphere and drag it to the north celestial pole. The simulator will read off the star's altitude and azimuth coordinates as you move it around.)
A. 0°
B. +39°
C. +90°
D. -45°