Final answer:
Personification in the first stanza of the poem creates an energetic and active mood by depicting the grasses dancing to the winds' tunes.
Step-by-step explanation:
The personification in the first stanza of the poem gives the tall green grasses human-like qualities as they 'dance' to the 'lively tunes' played by the wind. This use of personification contributes to an energetic, active mood in the stanza, as it evokes a sense of movement and rhythm. Thus, the answer to the question - How does personification affect the mood of the first stanza? - would be option B) it gives the stanza an energetic, active mood.