Read the passage from "The Pursuit of Happiness."

The woman on the far side of the desk looks at the floor,
Her head full of Ireland
and the potatoes that blackened and curled and rotted away.
We grew only sadness there
She wants to say.
But this she whispers instead:
'I have come to work as a chambermaid"
And the Important Person stamps her papers without hearing the rest.
"To scrub floors and wash linens until my hands are red and raw,
and I have polished happiness for my child
So she can become a teacher
with hands the color of cream."

Why does the author include a description of potatoes in this passage?

to explain the work the woman intends to do
to persuade the reader to avoid eating potatoes
to persuade the reader to support local farmers
to explain why the woman left Ireland for America