Answer:
C; Before the trial
Step-by-step explanation:
Letter C is the only answer that makes any sense.
Letter A is incorrect because when a person is about to go to sleep, their mind is at its foggiest point in the course of a day, so it wouldn't make sense to read the report at that time since it's likely the officer would miss certain aspects of the report.
Letter B is incorrect because it is physically impossible for the officer to look at the report every second of every day, since they would need to do things such as sleep, eat, and use the faculties.
Letter D is incorrect because it is unlikely that the officer would be able to concentrate completely if he was in the company of friends, so he would likely miss certain aspects of the report similar to the reasoning of why letter A is incorrect.
Therefore, the answer must be letter C.