The following sentence has been split into four segments, where the first segment (S) is fixed. Rearrange the remaining jumbled segments (A, B, C, D) to a form a coherent and meaningful paragraph. S: Space exploration expands human knowledge A: About distant planets B: through advanced research missions C: and scientific observations D: beyond Earth’s atmosphere

1. B - C - D - A
2. D - B - C - A
3. A - D - B - C
4. C - A - D - B