Final answer:
The correct answer is C. Investigators should inform management of only the basics of the investigation in case they are involved.
Step-by-step explanation:
The correct answer is C. Investigators should inform management of only the basics of the investigation in case they are involved. In a fraud investigation, it is crucial for investigators to be experienced and objective professionals (option A), closely guard all hypotheses regarding guilt or innocence (option B), and follow appropriate investigative techniques (option D). However, informing management of only the basics of the investigation in case they are involved can compromise the integrity of the investigation and potentially lead to conflicts of interest.