It Is Most Accurate to Say That

It is most accurate to say that

A) because they are correlational in nature, valid conclusions can never be drawn from quasi-experimental research designs.
B) quasi-experimental research will generally have higher internal validity in comparison to true experiments.
C) although they will generally have some threats to internal validity, quasi-experiments can sometimes be used to draw inferences about the causal relationships among variables.
D) quasi-experiments are less scientific than other types of research designs.