Why did the Supreme Court make an exception to the principle that "ignorance of the law does not excuse" in the case of a woman who failed to comply with a Los Angeles law requiring ex-convicts who moved to the city to register?

Answer: The correct answer is : The defendant had not been given due notice of the law.

Explanation: We all have a duty to know the laws, the legislator, by promulgating and publishing them, informs us about them. Yes, despite knowing them, we ignore them, our ignorance is guilty and cannot exempt us from all the sanctions established by the laws in case of non-compliance.