Question

What does William Wordsworth mean by "dances with the daffodils" in the following bolded lines? I wandered lonely as a cloud That floats on high o'er vales and hills, When all at once I saw a crowd, A host, of golden daffodils; Beside the lake, beneath the trees, Fluttering and dancing in the breeze. Continuous as the stars that shine And twinkle on the milky way, They stretched in never-ending line Along the margin of a bay: Ten thousand saw I at a glance, Tossing their heads in a sprightly dance. The waves beside them danced; but they Out-did the sparkling waves in glee: A poet could not but be gay, In such a jocund company: I gazed—and gazed—but little thought What wealth the show to me had brought: For oft, when on my couch I lie In vacant or in pensive mood, They flash upon that inward eye Which is the bliss of solitude; And then my heart with pleasure fills, And dances with the daffodils. He has to go to that field every time he wants to be happy. The memory of the daffodils can bring him happiness. Happiness is a state of mind that is never really real. There is no way to be truly happy without flowers nearby.
the bolded lines are: And then my heart with pleasure fills,
And dances with the daffodils.

Answer 1

When he remembers the daffodils, they bring happiness to his heart and give him the same feeling he had when he first saw them. 

Answer 2

The answer is "he feels happy again" or option B. When he was laying on the couch and he thought about the flowers he automatically got happy because of how beautiful nature is to him and the flowers reminded him of a long line of dancing in the breeze.

Hope this helps!