Answer : A. a Greek myth
Among the phrases above, the phrase "a Greek myth" is correctly capitalized. You can only capitalized proper nouns. Proper nouns include names of persons, places, and organizations. In the second option, the word king in the phrase "Martin Luther King day" should not be capitalized because it is not a proper noun so do with the grocery in "an Italian Grocery" and winter in "a cold, snowy Winter". The Greek in the phrase "a Greek myth" is correctly capitalized because it is a proper noun.
