The most serious problem with aggression is that A. it can cause property damage. B. we remove the obstacle that is the cause of our frustration. C. we aim it at people or things that are not the cause of our frustration. D. it's sometimes necessary to change our goals

The most serious problem with aggression is that C. we aim it at people or things that are not the cause of our frustration. Thus, we unintentionally hurt the people we love just because we feel anger towards something that has happened, that doesn't necessarily involve them at all. Although other options are also things that can happen when you feel angry, they are not the most serious problem as hurting your loved ones is.