Final answer:
Lt. Colonel C.T. Trowbridge refers to Lieutenant Colonel Charles Young, the highest-ranking African American military officer at the outbreak of World War I.
Step-by-step explanation:
Lt. Colonel C.T. Trowbridge refers to Lieutenant Colonel Charles Young, who was indeed a military officer. As the highest-ranking African American officer at the outbreak of World War I, Lt. Col. Charles Young was notable for his confrontation against military efforts that aimed to force him into retirement due to his race. From the given options, the answer would be a military officer. This determination is based upon historical records of Charles Young's service during a pivotal moment in American military history.