Answer: I would contend that the right answer is the C) A rare bird is captured from the wild and brought into captivity at a zoo.
Explanation: Just to elaborate a little on the answer, it can be added that green literature includes texts that focus and reflect on serious environmental concerns, such as genetic engineering and global warming, to name a few, as well as on the deep observation and experience of the natural world. For that reason, the topic of a rare bird that is captured from the wild and brought into captivity at a zoo would most likely be explored in a green story. A green story could use as a case study the testimony of a farmer that is struggling to get his crops to grow due to flooding issues — possibly caused by global warming — but that in itself would not be the main theme. The discovery in option A could be discussed in a scholarly scientific essay, and option D should not, in my opinion, be considered green literature.