Question

at the ancient egyptian city of syene, the sun was directly overhead only at summer solstice. thus, syene must have been very close to:
a. the tropic of cancer.
b. the prime meridian.
c. the equator.
d. the tropic of capricorn.

Explanation:

Syene (modern - day Aswan) is located near the Tropic of Cancer. At the summer solstice, the Sun is directly overhead at the Tropic of Cancer. The prime meridian is a longitude line, the equator is the 0° latitude line with different Sun - overhead timing, and the Tropic of Capricorn is in the Southern Hemisphere where the Sun is overhead at the winter solstice (for the Northern Hemisphere). So Syene must be very close to the Tropic of Cancer.

Answer:

a. the Tropic of Cancer