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 for 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: The term "hippocampus" is defined as one of the complex structures of an individual's brain and it is being embedded deeply inside the temporal lobe of the person. It is often considered as a vulnerable and plastic structure that generally gets damaged by a certain stimuli.

The hippocampus plays an important role in the memory and learning processes i.e, it is due to the hippocampus an individual can store information in the short-term and the long-term memory. However, explicit memory of an individual is often associated with the hippocampus.

In the question above, the given statement signifies that Lara's hippocampus wasn't fully developed by the age of eighteen months.

Question Options:

A. medulla

B. hippocampus

C. thalamus

D. reticular formation

HIPPOCAMPUS.

Explanation: This is likely due to the fact that her HIPPOCAMPUS, which is involved in storing explicit memories, was not fully developed at that age.

The hippocampus can be defined as a part of the brain located inside the temporal lobe, consisting mainly of grey matter. It is a component of the limbic system and plays a role in memory and emotion. It has a major function in learning and memory.