Question

Let seed be grass, and grass turn into hay:
I’m martyr to a motion not my own;
What’s freedom for? To know eternity.
I swear she cast a shadow white as stone.
But who would count eternity in days?
These old bones live to learn her wanton ways:
(I measure time by how a body sways).

Source: Roethke, Theodore. “I Knew a Woman.” The Collected Poems of Theodore Roethke. New York: Random House Inc., 1961. Poetry Foundation. Web. 9 June 2011.

Which line is an example of the poetic technique metonymy?

“Let seed be grass, and grass turn into hay:”
“I’m martyr to a motion not my own;”
“I swear she cast a shadow white as stone.”
“These old bones live to learn her wanton ways:”