Investigators must provideevidence of qualificationsto conduct the study.

ICH E6(R2) 4.1.1:“The investigator should be qualified by education, training, and experience to assume responsibility for the proper conduct of the trial.”

ICH E6(R2) 8.2.10:Essential documents include thecurriculum vitae (CV)or other documents evidencing investigator qualifications, submitted to both sponsor and IRB/IEC.

Proof of citizenship (A) and letters of recommendation (B) are irrelevant. A copy of a medical license (D) may be provided but isnot specifically requiredby ICH. The CV is the universally required document.

Thus, the correct answer isC (Curriculum vitae).