The correct answer is C) maximum declination north. At the summer solstice, the Sun reaches its maximum declination of approximately 23.5° north of the celestial equator. This is the point where the Sun appears to be at its northernmost position in the sky from the perspective of an observer on Earth. The summer solstice marks the first day of summer in the Northern Hemisphere and the beginning of the Sun's movement back towards the south. The other options are incorrect because: A) the Sun is at 0° declination going northward, not southward; B) the maximum declination is north, not south; and D) the Sun is at maximum declination north, not 0° declination going southward.