What type of amnesia involves forgetting events that occurred before an injury or trauma?

Retrograde amnesia is the correct answer because it specifically refers to the loss of memories that were formed before a particular incident, such as an injury or trauma. This type of amnesia can occur following various events, including head injuries, strokes, or psychological trauma, where individuals find it difficult to recall past experiences or information that was learned before the traumatic event.

In contrast, anterograde amnesia involves the inability to create new memories after the onset of the amnesia, which means individuals may retain memories formed prior to the injury but struggle to remember or learn anything new. The option describing usually temporary amnesia does not capture the specific characteristics associated with retrograde amnesia, as this type can be either temporary or permanent depending on the underlying causes. Semantic amnesia, on the other hand, refers to the loss of memory for factual knowledge or concepts, rather than personal experiences or events that occurred prior to an injury. Thus, the emphasis on forgetting events that took place before the trauma is what makes retrograde amnesia the appropriate choice.