Under TCPS 2, Excluding women from research is ethically unacceptable unless the exclusion is related to the nature and scope of the research question.

• A. Never ethically acceptable.
• B. Ethically acceptable because this protects women from the risks of research.
• C. Ethically unacceptable, unless the exclusion is related to the nature and scope of the research question.
• D. Ethically necessary when a woman is pregnant or breastfeeding.

Answer: (C)

In TCPS 2, who is invited to participate in research should be chosen fairly and for reasons that are tied to the study itself, not because of bias or unfounded protection. Excluding women from research is not allowed simply on the basis of their gender; inclusion should be the default unless there is a legitimate, study-specific reason that relates directly to the nature and scope of the research question or to participant safety.

That’s why the best answer says it’s ethically unacceptable to exclude women unless the exclusion is tied to the research question itself. If the study design, measurements, or risks are such that including women would not address the question or would confound results, then a justified, narrow exclusion may be appropriate. This preserves respect for women as participants, supports equitable access to the potential benefits of research, and avoids unjust discrimination.

The other options imply blanket or misdirected reasons for exclusion (absolute prohibition, protective justification, or pregnancy-related necessity) that TCPS 2 does not endorse as overarching rules. Exclusion should always be a careful, justified choice anchored in the study’s aims and risk assessment.