Read the following lines from Wordsworth's poem and answer the question.

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.

Which word from the stanza can you use as a clue to determine the meaning of the word "vales"?

hills
host
lonely
trees