how did the selction process affect elie and Email ?

"email"? I'm not sure what you mean here. The selection process was obviously stressful. Either you were useful or you were not. Early on Elie learned to lie about his age and background. He didn't want to be separated from his father. He also didn't want to be too young . He said he was a farmworker/labor person. He had to give the Nazis an excuse to want him alive.