Final answer:
Dissociative amnesia involves the client's inability to remember important personal information.
Step-by-step explanation:
The type of dissociative disorder that involves the client's inability to remember important personal information is dissociative amnesia. Dissociative amnesia is a condition where a person experiences memory loss for personal information and past events. It can include both retrograde amnesia, where the person forgets past memories, and anterograde amnesia, where the person has difficulty forming new memories.