Final answer:
The number of adult volunteers increases from Group A to Group D in an ascending order, each having one more volunteer than the previous group. Therefore correct option is D
Step-by-step explanation:
The relationship between the number of adult volunteers and the groups of students is that the number of adult volunteers increases as the group of students changes from A to D. Therefore, the correct statement that describes this relationship is: The number of adult volunteers increases as the group of students changes from A to D.
This can be confirmed by examining the values presented for each group. Group A has 2 adult volunteers, Group B has 3, Group C has 4, and Group D has 5. This shows a clear ascending order from group A to D, with each subsequent group having one more volunteer than the previous group.