Final answer:
After joining the Royal Army Medical Corps, Fleming was initially sent to the Western Front and later transferred to the Inoculation Department in France. It was during this time that he made important contributions to wound infection research.
Step-by-step explanation:
Immediately after Alexander Fleming joined the Royal Army Medical Corps during World War I, he was sent to the Western Front in Belgium and France. However, due to his skills in bacteriology, he was later transferred to the Inoculation Department at the British Expeditionary Force headquarters in Rouen, France. It was during his time there that he made significant contributions to wound infection research, which eventually led to the discovery of penicillin.
Learn more about Alexander Fleming's role in World War I