Two cars pass each other in opposite direction. How long would they take to be 500 km apart? I. The sum of their speeds is 135 km/hr. II. The difference of their speed is 25 km/hr.

1. A Option A: I alone sufficient while II alone not sufficient to answer
2. B Option B: II alone sufficient while I alone not sufficient to answer
3. C Option C: Either I or II alone sufficient to answer
4. D Option D: Both I and II are not sufficient to answer
5. E Option E: Both I and II are necessary to answer

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