Hippocampus
It is a small part of the brain located on the medial temporal love and forms important part of the limbic system, these are the regions that regulates emotions. This is also associated with memory, spatial navigation, consolidation of information. Damage to this area can cause memory loss, difficulty establishing memory . In Alzheimer's disease hippocampus is one of the first regions in the brain to be affected.
Both viral vectors and bacterial plasmids can be used to transfer genes into an organism. An invitro fertilisation could maybe be helpful, but not with engineered genes, but existing genes.
A) viral vectors is the best answer is viruses can be used to infect plants and change their DNA- bacteria aren't as good, as they can mostly be used to modify other bacteria only
