In a clinical trial,researchers might influence the selection of participants into a group (intervention or control) ,hence introducing bias into the study.What can be done to prevent from this threat to the validity of the study?

A) Confounding
B) Randomization
C) Concealment of random allocation
D) Masking
E) Effect modifiers

Validity

The accuracy with which a study reflects the true situation.

Bias

A systematic error or deviation from the truth in results or inferences that can affect the validity of research findings.

Randomization

is a process used in experimental designs to allocate subjects randomly to different groups to ensure each group is similar and that the treatment effects can be attributed solely to the treatment being tested.