Question

read the sentence
the children, who were lucky, received presents.
which statement accurately describes the sentence?
the sentence includes a restrictive clause.
the sentence has an appositive that is essential for understanding.
the sentence contains a non - restrictive appositive
the sentence describes exactly which children received presents.

Explanation:

1. A non-restrictive clause is set off by commas, adds extra non-essential information, and uses "who/which". Here, "who were lucky" is set off by commas and does not define which specific children (it just adds extra info about all the children).
2. A restrictive clause would not use commas and would specify which children, which this does not do.
3. An appositive is a noun/phrase renaming another noun, which this clause is not.

Answer:

The sentence contains a non-restrictive appositive