Read the sentence. Elsa thought she was incapable of finishing the marathon, so she was delighted when she finally saw the finish line. How does the prefix "in-" in the word "incapable" clue the reader in to how Elsa is feeling? It explains why Elsa will not cross the finish line. It indicates why Elsa has never tried a marathon before. It demonstrates why Elsa is so relieved to see the finish line. It reveals why Elsa has become such a confident competitor.