Final answer:
Descriptive statistics are represented by specific percentage values in option b, as these values summarize and present the data in a straightforward manner without making further inferences.
Step-by-step explanation:
The part of the study that represents descriptive statistics is option b) 31% of parents planning to financially support their children through college graduation and 6% through the start of college. Descriptive statistics involve presenting, organizing, and summarizing data in order to describe the basic features of the data in a study. This is typically achieved through the use of graphs, tables, and numerical measures such as percentages, mean, median, and mode. In this case, the percentage values detailing the parents' plans provide a clear, concise picture of the data collected without making any further inferences or predictions.