In accordance with ICH, which of the following is an acceptable protocol review frequency for...

IRBs must review protocols at least annually to ensure ongoing subject protection.

21 CFR 56.109(f):“An IRB shall conduct continuing review of research at intervals appropriate to the degree of risk, but not less than once per year.”

ICH E6(R2) 3.1.4:“The IRB/IEC should conduct continuing review of each ongoing trial at intervals appropriate to the degree of risk, but at least once per year.”

This establishes12 monthsas the minimum required interval. More frequent reviews (e.g., 6 months) may occur for higher-risk studies, but longer intervals (24–36 months) are not permitted.

Correct answer:B (12 months).