Direction : Read the extract given below and answer the questions that follow by selecting the correct/most appropriate options :
                                          Light Brigade

Half a league, half a league,
Half a league onward,
All in the valley of Death
Rode the six hundred.
"Forward the Light Brigade!
Charge for the guns !" he said.
Into the valley of Death
Rode the six hundred.
Forward, the Light Brigade !"
Was there a man dismay'd?
Not tho' the soldier knew
Some one had blunder').
Theirs not to make rep.y,
Theirs not to reason why,
Theirs but to do and die.
Into the valley of Death
Rode the six hundred. Which literary device is used in the expression, 'to do and die' ?