What is the difference between true experimental designs and quasi-experimental designs?

A) True experimental designs use random assignment, whereas quasi-experimental designs do not.
B) True experimental designs use control groups, whereas quasi-experimental designs do not.
C) Quasi-experimental designs use random assignment, whereas true experimental designs do not.
D) Quasi-experimental designs use control groups, whereas true experimental designs do not.

The main difference between true experimental designs and quasi-experimental designs is that true experimental designs use random assignment, whereas quasi-experimental designs do not. Random assignment is a crucial component for making causal inferences about the relationship between independent and dependent variables. Quasi-experimental designs lack random assignment, which makes it difficult to establish cause and effect relationships. While both true experimental and quasi-experimental designs may use control groups, this is not the defining characteristic that distinguishes them from each other.