What is the antecedent for "It" in line 9 in "The World Is Too Much with Us"? a) Boon b) Nature c) spending

The antecedent for "It" in line nine of Wordsworth's "The
World Is Too Much With Us" is, in general,
nature.

Specifically, the "It" refers back to "The Sea" in
line five and "The winds" in line six.  But it also encapsulates the "Nature" of line
three.  The sea and the winds comprise nature in the poem together with, for example,
the "pleasant lea" that appears later in the poem.

The use
of the pronoun here provides unity to the poem.  The pronoun recalls everything the
speaker has said up to that point about nature.   This pulls the octave together (an
octave is usually the first eight lines of an Italian sonnet, but here it's the first
8.5) and in a sense summarizes it.  The octave transitions then into the abrupt "--Great
God!" of the sestet.