Which statement best describes the structure of “I Hear America Singing”?

The poem is loosely structured and contains rhyme.
The poem is loosely structured and contains repetition.
The poem has a strict structure, including a specific rhythm.
The poem has a strict structure, including repetition.

(“I Hear America Singing”

I hear America singing, the varied carols I hear,
Those of mechanics, each one singing his as it should be blithe and strong,
The carpenter singing his as he measures his plank or beam,
The mason singing his as he makes ready for work, or leaves off work,
The boatman singing what belongs to him in his boat, the deckhand
singing on the steamboat deck,
The shoemaker singing as he sits on his bench, the hatter singing as
he stands,
The wood-cutter's song, the ploughboy's on his way in the morning,
or at noon intermission or at sundown,
The delicious singing of the mother, or of the young wife at work,
or of the girl sewing or washing,
Each singing what belongs to her, and to none else,
The day what belongs to the day – at night, the party of young
fellows, robust, friendly,
Singing, with open mouths, their strong melodious songs.) ^^^ The poem

The comma attempts to set apart an essential element.