Answer:
A. Onomatopoeia
Step-by-step explanation:
If the underlined portion of the stanza is where hippos grunt, then it is an example of the sound device known as onomatopoeia. Onomatopoeia is a figure of speech in which sounds coming from nature are imitated (ex. POP! BANG! WOOSH!). So, the verb 'grunt' evokes some animal sounds that can be heard in nature.
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