If both the pipes are opened, how many hours will be taken to fill the tank? I. The capacity of the tank is 400 litres. II. The pipe A fills the tank in 4 hours. III. The pipe B fills the tank in 6 hours.

1. A Option A: Only I and II
2. B Option B: Only II and III
3. C Option C: All I, II and III
4. D Option D: Any two of the three
5. E Option E: Even with all the three statements, answer cannot be given.

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