-Parentheses are used to set off a participle word or words which can be omitted, but does not affect the whole thought of the sentence. In addition, parentheses could also be used to add a specific detail about the word beside it.
-Dashes are used to set additional information off. Dashes are commonly used if the words it enclosed already has a comma or commas in it, just to avoid confusion.
In this excerpt of his speech, Wiesel encourages the world to 'take sides' and work to end suffering (A).
He does not want people to be passive and simply stay neutral (C) or on the sidelines (B). He wants people to take position: "I swore never to be silent," "We must always take sides." Through parallelism, he also blames inaction for feeding into the problem: "Neutrality helps the oppressor" // "Silence encourages the tormentor."
Neither does he believe that thinking about race, religion or political views (D) is enough. He is urging people to take action to defend citizens from discrimination. This is shown by the use of the action verb "interfere."