Answer:
they're all the same? from what i see...
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.
Answer:
I helped my younger brother build a sand castle at the beach.
Explanation:
I did the test and got it right ;)
