The following salad contains spring mix, bell peppers, carrots, cucumbers, mushrooms, bacon bits, egg, Colby Jack cheese, croutons, and ranch dressing. What change would make the most significant reduction in the amount of fat in this salad

If you have no information on the calorie content of these additions it would be impossible to say. However, we can definitely say it’s not the peppers, carrots, cucumbers, mushrooms, eggs, or croutons. You would need information regarding how much cheese, bacon or dressing is in the salad. At face value one may assume it’s the bacon, however, ranch dressing can have a significant amount of fat in it (as do most salad dressings). Without amount of each ingredient, this question can not be answered. Ranch dressing or bacon are your safest bets.