Final answer:
Ethical dilemmas are most likely to arise in observational studies when observation is disguised or undisguised.
Step-by-step explanation:
Ethical dilemmas are most likely to arise in observational studies when observation is disguised or undisguised.
In disguised observation, the observers conceal their true purpose of the study from the participants. This raises ethical concerns because it involves deception and may violate the participants' right to informed consent.
On the other hand, in undisguised observation, the observers openly observe and record the participants' behavior without concealing their purpose. Ethical dilemmas can arise in undisguised observation if the study involves sensitive or private behaviors where participants may feel their privacy is being invaded.