Read these lines from Philip Freneau's the "Indian Burying Ground" and answer the question. In spite of all the learned have said,

I still my old opinion keep;

The posture that we give the dead,

Points out the soul's eternal sleep.

Not so the ancients of these lands—

The Indian, when from life released,

Again is seated with his friends,

And shares again the joyous feast.

His imaged birds, and painted bowl,

And venison, for a journey dressed,

Bespeak the nature of the soul,

Activity, that knows no rest.

The shift in the poem's rhythm in the last stanza signifies .

a sense of history that is present
the speaker's uncertain identity
that the poem is a sonnet
an irregular rhyme scheme