Which theme is best supported by the descriptive detail in this passage from My Antonia?

The rabbits were unusually spry that afternoon. They
kept starting up all about us, and dashing off down the
draw as if they were playing a game of some kind. But
the little buzzing things that lived in the grass were all
dead - all but one. While we were lying there against the
warm bank, a little insect of the palest, frailest green
hopped painfully out of the buffalo grass and tried to leap
into a bunch of bluestem. He missed it, fell back, and sat
with his head sunk between his long legs, his antennae
quivering, as if he were waiting for something to come
and finish him

The prairie is a place filleu with life.

There is a tension between life and death on the
prairie.

Rabbits, like people, must cope with life's hardships.

All living things on the prairie worry about predators.