The Primary Reason Descriptive/correlational Research Cannot Determine Conclusively That Variables

The primary reason descriptive/correlational research cannot determine conclusively that variables have a cause and effect relationship is because in conducting the research

A) the researcher cannot control events or manipulate variables.
B) only an experimental group is used.
C) the data collected frequently comes from direct observations or statements made by subjects.
D) the researcher observes behaviour under artificial situations.