German A1 Level Question

Sentence 'b' correctly uses 'Osten' to indicate a direction, meaning 'east'. Sentence 'a' is incorrect because the sun sets in the West, not the East. Sentence 'c' is incorrect because it implies a direction of wind, but 'from the east to the south' is possible, though less common. Sentence 'd' is correct, but 'Osten' should be lowercase unless it's part of a proper noun.