At the end of this passage why is everyone so motionless and quiet

D) They are about to watch someone die, so they are showing respect.  

Explanation:

Midway up the slope between the bridge and fort were the spectators -- a single company of infantry in line, at "parade rest."

i go to the store and buy some cheese,suddenly there was akward silence.   out of no where comes a ninja, and he takes an apple, and chokes the cashier, until he passes out.   the disapeared in a puff of smoke.   the cashier went to the doctor, and everything was fine again.   they all lived happily ever after without anymore ninjas.

the end

go to buy cheese= exposition

akaward silence= rising action

ninja chokes the cashier= climax

cashier goes to the doctor= falling action

they live happily ever after= resolution

the central idea is basically saying that juveniles that have committed a crime will not have the same consequences as the   adults that have. they will have a softer punishment than what the adults have that is harsh in some ways.