Which method is least likely to retain the nutrients in vegetables?

Boiling is the method least likely to retain the nutrients in vegetables. When vegetables are boiled, they are submerged in water, and many of the water-soluble vitamins, such as vitamin C and some B vitamins, can leach out into the boiling water. This nutrient loss can be significant, especially if the vegetables are cooked for an extended period.

In contrast, methods like steaming and microwaving expose the vegetables to less water and often use shorter cooking times, which helps preserve more nutrients. Roasting, while it may cause some nutrient loss due to high temperatures, usually retains most of the nutrients because the vegetables are not in direct contact with water. Therefore, boiling is the method that is most likely to lead to substantial nutrient loss in vegetables.