Final answer:
King Minos imposed the duty of sending an annual tribute of young men and women for the Minotaur on Athens.
Step-by-step explanation:
The duty that King Minos imposed upon Athens was a) Annual tribute of young men and women for the Minotaur. According to the myth, after Athens was defeated by Crete, Minos demanded that every year, Athens must send seven young men and seven young women to Crete to be fed to the Minotaur, a dreadful monster that resided in the labyrinth of the Minoan palace complex. This tribute continued until the Athenian hero Theseus volunteered to go as one of the tributes and successfully slayed the Minotaur with the help of Minos's daughter, Ariadne.
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