Which Statement Best Describes the Term Descriptive Designs

Which statement best describes the term descriptive designs?

A) They are studies that measure two or more variables and their relationship to one another; they are not designed to show causation.
B) They are methods used to assign participants to different research conditions, so that all the participants have the same chance of being in any specific group.
C) They are research designs that include independent and dependent variables and random assignment of participants to control and experimental groups or conditions.
D) They are study designs in which a researcher defines a problem and variable of interest but makes no prediction and does not control or manipulate anything.