Cannon to right of them,

Cannon to left of them,

Cannon behind them

Volley’d and thunder’d;

Storm’d at with shot and shell,

While horse and hero fell,

They that had fought so well

Came thro’ the jaws of Death,

Back from the mouth of Hell,

All that was left of them,

Left of six hundred.

Why does Tennyson most likely repeat the word "cannon" in the first three lines of the excerpt?

to prove that the enemy had a larger store of weapons
to identify the primary weapon used in the battle
to demonstrate the fear the soldiers must have felt
to show that the assault on the soldiers was nonstop