Final answer:
The Earth's numbered position in its orbit around the sun that corresponds to the summer solstice in the northern hemisphere is the 3rd position.
Step-by-step explanation:
The summer solstice in the northern hemisphere corresponds to June 21. This is the day when the North Pole is in constant sunlight, while the South Pole experiences 24 hours of darkness. The Sun appears at the zenith for places located on the Tropic of Cancer, which is approximately 23° N latitude.
Therefore, the numbered position of the Earth in its orbit around the sun that corresponds to the summer solstice in the northern hemisphere is c) 3rd.