Final answer:
A policy focused on additional ethical scrutiny for research involving pediatric subjects is most directly aimed at upholding the principle of respect for persons, providing extra protection for vulnerable populations.
Step-by-step explanation:
The principle of respect for persons is central in research involving human participants, as it necessitates prioritizing the dignity and autonomy of those individuals. Of the given options, the measure that most directly upholds this principle is A) A policy requiring that any research involving pediatric subjects undergo an extra level of ethical scrutiny prior to approval.
This policy emphasizes the need for heightened protection for vulnerable populations, such as children, ensuring that their rights and well-being are thoroughly considered before they participate in research. The other options, while important, do not directly address the principle of respect for persons as much as the added ethical scrutiny of research involving minors does.