The answer is B: Less than a decade ago, the HSUS...an affiliate [Human Society International].
Brackets are used to give the writers (when they need to add information) an opportunity to add an explanation, or emphasis to a word, or change a <em>quote to fit to a sentence, but without changing the meaning of the text</em>. In A) <em>global work</em> doesn't need explanation; C) <em>decade</em> doesn't need explanation; D) <em>HSUS</em> was already explained in the first sentence of the text.
The answer is D i believe!!
The mention of the sun rising in the unripe season tells of spring. The last stanza describes the narrator chasing the deer until noon. This then tells that it was morning when he spotted the deer under a laurel tree.