Final answer:
The DoD principal in charge of developing harassment prevention and response policy is likely the Under Secretary of Defense for Personnel and Readiness (USD(P&R)).
Step-by-step explanation:
The individual serving as the DoD principal responsible for developing DoD harassment prevention and response policy is likely the Under Secretary of Defense for Personnel and Readiness (USD(P&R)). Each cabinet department, including the Department of Defense, is led by a secretary who reports directly to the president. Within these departments, there are numerous undersecretaries responsible for various aspects of the department's functions. The USD(P&R) is typically responsible for matters pertaining to personnel policies, including those related to preventing and responding to harassment.