Final answer:
Nurse Chris should choose plain popcorn as the healthiest snack option for Derek since it is a whole grain, high in fiber, and low in calories.
Step-by-step explanation:
The question is asking which snack Nurse Chris should select for Derek. Among the options provided, plain popcorn is the best choice as it is a healthier snack compared to the others. A chocolate bar and potato chips are high in saturated fats and sugars, which are not recommended for a healthy diet. Fruit juice, although it sounds healthy, often contains a high amount of sugar as well and lacks the fiber found in whole fruits. In contrast, plain popcorn is a whole grain, contains fiber, and is low in calories when not covered with butter or sugar.