Ali drove at 50 km per hour for first three hours of his trip. Then due to heavy traffic he drove at 40 km per hour for two hours. Find his agerage speed for the trip?

1. A Option A: 48 km per hr
2. B Option B: 45 km per hr
3. C Option C: 46 km per hr
4. D Option D: 43 km per hr
5. E Option E: none

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