The two lines from the text that demonstrate that nature had the power to change Wordsworth's mood are:
"Out-did the sparkling waves in glee:" (line 14)
"A poet could not but be gay" (line 15)
Explanation:
I Wandered Lonely as a Cloud by William Wordsworth is a poem that has as one of the principal themes the involvement of humans into the beauty of nature and its marvels, clear examples of this are the lines 14 and 15 where the author shows how the nature seem incredible to him and he has no other option but to be glad by the opportunity of seeing those events.
I had the same question and the answer was knowledgeable but you didn't give options so our questions might be talking about completely different passages
