Adam suffered a brain injury in a motorcycle accident that makes it impossible for him to form new memories. He can, however, remember his life experiences before the accident. Adam's memory difficulty most clearly illustrates:

Encoding Failure

Explanation:

Encoding Failure -

The term encoding is used, where the brain create memories by using any previous links or information.

Encoding failure is the condition of the brain, where the brain is unable to produce any memory for short term or long term.

The failure can be due to various reason like, accident, trauma or any action.

Hence, from the given information of the question,

The correct answer is Encoding Failure.