What wider warning does the involvement of doctors and scientists under Nazi rule create?

Correct answer: Professional knowledge without ethics can become a tool of repression

The direct answer is A: professional knowledge without ethics can become a tool of repression. Doctors and scientists possess specialised skills, so their work can help a state classify people, justify false racial theories, conduct abusive experiments or design harmful policies when moral limits are abandoned. Education alone does not guarantee goodness; professionals must respect human dignity, informed consent, equality and responsibility. B is wrong because science can be influenced or misused by political power. C is wrong because medicine has historically been affected by laws and governments. D is wrong because educated people, like others, can participate in wrongdoing. A is correct because it gives the wider warning about knowledge without ethics. Memory cue: skill needs conscience; professional duty cannot be separated from human rights.