B - A video could show epidemic intelligence officers collecting clues about diseases.
Explanation:
i believe the answer is option b. one important trait of detectives is that they collect clues (to solve cases), but in this case, since dr. dowell is referring to the epidemic intelligence service officers as "disease detectives", the video would show them collecting clues about diseases and not crimes.
option a, c and d are not as specific to the word "detective" so option b is more apt.