Trent is reading these lines from "Winter-Time" by Robert Louis Stevenson.

Black are my steps on silver sod;

Thick blows my frosty breath abroad

Which fact would best help Trent understand this poem’s meaning?

Sod is another name for grass, and it often looks silvery-white in the winter.
People often wear black shoes and warm gloves in the winter.
Many animals migrate to warmer climates during the winter.
During the winter, the clouds are very thick and look silver in the sky.