Amy and Bernie started from the same place.

Amy started at 9 am, by 11:30 am, Amy would have covered 150 miles at 60mph.

Bernie starts at 11:30 am and moves towards the south.

After every 1 hour, the distance between them increases by 90+60 miles = 150 miles.

At 12:30 pm, the distance would be 300 miles.

Then for the distance between them to be 600 miles. It would take another 2 hours. Hence at 2:30 PM, distance between Amy and Bernie would be 600 miles.

D is the answer.

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