Lara is trying to remember events from her life as an 18-month-old. however, as hard as she might try, she has no conscious memory of anything that occurred before her third birthday. this is likely due to the fact that her which is involved in storing explicit memories, was not fully developed at that age.

hippocampus            

Explanation:

Hippocampus: It is the small organ, and curved pattern in the brain, which plays a significant role in the limbic system. This is intricate in making new memories and connections to emotions and learning. Responsible for long-term memory.

If any part of the hippocampus gets damaged by accident or any illnesses like Alzheimer's disease, then the person may lose memory and may not be able to form new memory.

Example: Similarly, if the hippocampus isn't properly developed, as in Lara's case, then a person might not be able to recover his or her explicit memory.

a is the final ! : )