This question presents a sentence. The underlined parts of the sentence might display errors in grammar, correctness, and style. Choice 'A' repeats the underlined part as-is -- meaning that it is the best and most correct expression. The other four choices present other options. When evaluating your choices, choose the one that is most effective, grammatically correct, and precise and follow the conventions of standard written English.
The League of Nations was created after World War I, and its goal was to prevent war from ever happening again.