Which of the quotations from this story reveal an objective point of view?

The objective point of view is limited to what the narrator sees or hears.  He can not project into others thoughts or motives.  Much of an objective point of view is dialogue so any point in "An Occurrence At Owl Creek Bridge" where there is actual dialogue is from an objective point of view.  A good example of this is in section two of the story when Peyton Farquhar is speaking with the soldier who approaches his wife and him while they sit on the bench.  Below is a little of that conversation:

"The Yanks are repairing the railroads," said the man, "and are getting ready for another advance. They have reached the Owl Creek bridge, put it in order and built a stockade on the north bank. The commandant has issued an order, which is posted everywhere, declaring that any civilian caught interfering with the railroad, its bridges, tunnels or trains will be summarily hanged. I saw the order."

"How far is it to the Owl Creek bridge?" Farquhar asked.

"About thirty miles."

"Is there no force on this side the creek?"

"Only a picket post half a mile out, on the railroad, and a single sentinel at this end of the bridge."

"Suppose a man--a civilian and student of hanging--should elude the picket post and perhaps get the better of the sentinel," said Fharquar, smiling, "what could he accomplish?"

There is more objective point of view in the section of the story where the narrator describes Fharquar struggling in the river.  I hope this give you an idea of what to look for in reading the story.  That way you can choose the quotations you want to use.