Read the following passage and then answer the question.
“Will no one tell me what she sings?--
Perhaps the plaintive numbers flow
For old, unhappy, far-off things,
And battles long ago:
Or is it some more humble lay,
Familiar matter of to-day?”
"The Solitary Reaper." William Wordsworth (1770-1850)
What does the poet mean by “plaintive numbers”?
A. sad songs
B. obvious facts
C. hopeful wishes
D. sweet notes