The theme that distinguish literature written in the realist era from earlier literature is everyday life and common subjects. The correct answer is A.
That would be true, but please, correct me if I'm wrong.
╔═.✵.══════════╗
A N S W E R
╚══════════.✵.═╝
☆ ☆ ☆
D
Evidence: "The ornithologists have been here," it's saying how the ornithologists were last seen there, which supports D being the correct answer.
Hope this helped, love! ☆☆ ☆