The Scarlett Letter by Nathaniel Hawthorne is set in the world of Puritanism, a time marked by great judgment against sin by the people as well as the religious leaders. When Hester Prynne was caught and convicted as an adulteress (because she had a child but had no husband living with her), she was sentenced to stand on the scaffold with her child for an entire morning. There she was exposed to the scrutiny of the accusing townspeople and not allowed to hide her face in shame. She was also forced to wear a scarlet letter on her breast to indicate her sin of adultery.
Some years later, after the townspeople have grown accustomed to Hester and her good works and are no longer afraid that her sin will somehow contaminate their lives, there is talk of allowing her to remove the letter. The person who brings her this news is her husband, Roger Chillingworth, though no one in town knows of his connection to Hester--by his choice.
In chapter fourteen of the novel, he and Hester (as well as Pearl) meet in the forest and he shares what he thinks will be good news for her:
Why, Mistress, I hear good tidings of you on all hands! No longer ago than yester-eve, a magistrate, a wise and godly man, was discoursing of your affairs, Mistress Hester, and whispered me that there had been question concerning you in the council. It was debated whether or no, with safety to the common weal, yonder scarlet letter might be taken off your bosom. On my life, Hester, I made my entreaty to the worshipful magistrate that it might be done forthwith!”
Your question asks what Hester's reply was to that idea, and this is her immediate response to Roger Chillingworth:
“It lies not in the pleasure of the magistrates to take off this badge,” calmly replied Hester. “Were I worthy to be quit of it, it would fall away of its own nature, or be transformed into something that should speak a different purport.”
Chillingworth does not argue with Hester but says the letter is a beautiful adornment and a woman must be able to choose what she will wear. He does not mention anything about what the letter stands for or whether it has done what the magistrates intended. Hester is the one who refers to that when she says the letter has a life of its own and no human, neither herself nor the magistrates, has the right to remove it.