"Doodle was both tired and frightened, and when he stepped from the skiff he collapsed onto the mud, sending an armada of fiddler crabs rustling off into the marsh grass. I helped him up, and as he wiped the mud off his trousers, he smiled at me ashamedly. He had failed and we both knew it, so we started back home, racing the storm. We never spoke (what are the words that can solder cracked pride?), but I knew he was watching me, watching for a sign of mercy. The lightning was near now, and from fear he walked so close behind me he kept stepping on my heels. The faster I walked, the faster he walked, so I began to run. The rain was coming, roaring through the pines, and then, like a bursting Roman candle, a gum tree ahead of us was shattered by a bolt of lightning. When the deafening peal of thunder had died, and in the moment before the rain arrived, I heard Doodle, who had fallen behind, cry out, "Brother, Brother, don't leave me! Don't leave me!" - The Scarlet Ibis
According to the story, which is likely the main reason Brother left Doodle behind?
Brother is frustrated that Doodle failed to achieve their goals
Brother was scared of the storm
Brother wanted to win the race
Brother had to chase after the ibis