If the underlined phrase is <em>having been warned by her mother, </em>then this is a nonessential perfect participial phrase.
Nonessential phrases are separated from the rest of the sentence by commas, and since this is a perfect participle, this is the only correct option.
moral principles that govern a person's behavior or the conducting of an activity.
So B,
Hoped I helped :)
The "mortgage crisis" could be one of the existing problems that should be provided with a solution accross the country. I hope my answer has come to your help. God bless and have a nice day ahead! Feel free to ask more questions.