Which is an example of a situation where deferential vulnerability might be a factor?

A college professor recruiting among their students

An army medical officer recruiting subjects among lower ranks

A physician recruiting patients to be subjects

An employer recruiting among persons who directly report to them

Question $5$

When an IRB is reviewing a research study and they are considering if a potential subject population is vulnerable, they should consider:

Has the researcher completed required training?

Is there a power differential between researchers and subjects?

Are the research procedures greater than minimal risk of harm?

Are there adequate resources to conduct the study?