Among the options you've provided, the unethical conduct during research is:
a. Non-disclosure of details of research
This option refers to failing to inform participants about the nature, purpose, and potential risks of the research, which is considered unethical. In research ethics, transparency and the informed consent process are vital to ensure that participants are fully aware and agreeable to what their involvement entails.
The other options (b through e) relate to ethical practices in research, such as ensuring voluntary participation, protecting privacy, ensuring anonymity, and obtaining informed consent.