What specifically is the "chain" being refers to in the Christmas carol

These chains are made of steel and are weighed down with "cash-boxes, keys, padlocks, ledgers, deeds, and heavy purses." ... This chain, then, is symbolic of Marley's business affairs and his pursuit of wealth when he was alive. Like Scrooge, he focused on enriching himself instead of caring about the plight of others.

Explanation:

Scrooge will learn that the chain serves as Marley's punishment. As those things were his only concern in life, Marley must carry them now and forever. Further, Scrooge learns that he himself has already forged a similar chain—but for seven years longer. Marley's appearance warns Scrooge of his potential fate.

answer; /// (the anagnorisis )

innocence can be defined as the lack of sin, relating it with the lack of guilt, also it can be a synonime of naivety. most people agree that sins are made out of experiences, intentionally or not, as well as you stop being naive once certain things happen to you throughout your life. so, with this explained, the chosen answers are:

when the boy saw the effects of war, he no longer viewed life as innocent.

the loss of innocence is a result of gaining experience and making mistakes.

one way to define innocence is as a lack of worldly experience or sophistication.