Concept:"Reconciling" means restoring friendly relations between people, so the opposite is "dividing", which means causing disagreement or estrangement.
Explanation:The sentence says Roxanne worked to do the opposite of reconciling her parents.
If she did not reconcile them, she would instead create a split or disagreement between them.
Among the options, "dividing" best expresses causing parents to be at odds with each other.
"Separating" simply means moving apart, "isolating" means keeping someone alone, and "destroying" is too broad and does not fit the relationship sense.
Answer:A. dividing