Step 1: Understand types of amnesia.
Retrograde amnesia refers to the inability to recall information or events that occurred before a traumatic incident. Step 2: Eliminate incorrect options.
Anterograde amnesia affects the formation of new memories after trauma.
Infantile amnesia refers to the inability to recall early childhood memories.
Posthypnotic amnesia involves memory loss following hypnosis. Step 3: Conclusion.
Therefore, the correct answer is Retrograde amnesia.