Lilly is a student in first grade. She enjoys hands-on science and math activities. Her teacher gave Lilly a basket of different types of apples. Lilly is able to classify the apples on the basis of more than one property. She can sort them by color and size. Lilly is showing characteristics of the of Piaget's Cognitive Development Theory.

Dr. redbull conducts a study to determine whether her new energy drink children perform better on spelling tests. she randomly assigns children to one of two groups: group 1 receives her energy drink and group 2 receives water. she then gives both groups a spelling test and compares the results. which of the following is true about this study? a. group 1 is the dependent variable and group 2 is the independent variable. b. this is a correlational study. c. group 2 is the experimental group. d. the independent variable is the type of drink the children receive.