If a 100ml solution contained 50% alcohol, what is the proof of the solution?

A team of researchers has decided to employ the high-risk research design in a longitudinal study of adolescent alcohol use. What will these researchers have to do to conduct such a study?

a. put their subjects in risky situations b. select subjects based on the presence of specific risk factors c. take the risk of investigating an unlikely cause d. assess the risky behaviors displayed by the subjects

The "last minute disclosure" is a recommended technique

Indicate whether the statement is true or false.