Final answer:
The exception mentioned in Subsection B of Section 709 is disclosure of information to law enforcement agencies.
Step-by-step explanation:
The exception mentioned in Subsection B of Section 709 is Disclosure of information to law enforcement agencies. According to the information provided, an investigator is allowed to reveal information relating to representation of a client to law enforcement agencies without the client's consent after consultation. This exception is explicitly authorized in order to carry out the representation.