The pronoun it in the following lines refers to 1464. iron was its edge, all etched with poison,
1465. with battle-blood hardened, nor blenched it at fight
1466. in hero's hand who held it ever,
1467. on paths of peril prepared to go
1468. to folkstead of foes. Not first time this
1469. it was destined to do a daring task.

through negative experiences we learn many things its sort of like karma if u do something bad to someone and u get a consequence u dont like the next time u wont do it again and as for positive ur not really learning anything and another example for negativity people didnt want barrack obama as president because they thought he was the worst and he was taking but now we have donald trump   and hes   is not anyone and shut down the government over sum petty stuff unlike barrack obama who shut down the government because they did not want to give health care to the community and now these people who want him out want him in now

this is a good question! i'll do some research and come back when i have the answer!

it would be d because the however is more proper and the comma is placed in the right spot