Final answer:
The location on Earth where Vega practically crosses your zenith is Sacramento, California (38º 35'N).
Step-by-step explanation:
The location on Earth where Vega practically crosses your zenith would be (c) Sacramento, California (38º 35'N). The north celestial pole, which is 90° from the celestial equator, would be at an angle equal to the observer's latitude. Therefore, for an observer at 38° N latitude, the north celestial pole would be 38° above the northern horizon. This means that Vega, which is located near the north celestial pole, would appear very close to the observer's zenith in Sacramento, California.