The bird flew north of the beach is the answer.
It is that one because A should have been " We should have left early."
B should have been " The three girls might have broken the records."
C should have been " The boys surrendered, but they should have fought."
However if you put D in that context " The bird flew north have the beach."
In the context that A, B and C are in it doesn't make sense.
Hope this helped. :)
