The line which includes an example of personification is the following one:
b. ". . . the trees unloose / their soft arms . . ."
Explanation:
Personification is a figure of speech in which non-human things acquire human traits so a certain idea can be conveyed.
Trees have no arms, so that is an example of personification. Plus, an adjective was used to describe those "arms": soft, which means those trees were described as having truly human characteristics, since there is nothing soft about a tree (except its leaves). The author probably meant those particular trees were kind in the sense of providing a feeling of serenity, in the same way a kind and gentle person would be able to do.
