Where did most enslaved africans end their journey?
a. slave castles in africa
b. plantations in the southern united states
c. plantations in the caribbean
d. warehouses in new york

Most enslaved Africans ended their journey in "C. plantations in the Caribbean," since they were brought primarily to this area in order to work in sugar mills and other plantations. Large numbers of slavers were indeed taken to plantations in the American South, however. 

In the explanation.

Explanation:

Electroencephalogram (EEG). Due to his problem with staying awake, Akira’s doctor has scheduled an overnight sleep study. Such studies often include the diagnostic method of Electroencephalogram (EEG), which can help to assess brain activity both during awake and sleep hours. This procedure will help to identify if Akira’s condition is a result of pathological electrical activity in his cerebral cortex. For example, if he is suffering from epilepsy.

Stimulants. In order to improve his condition at school, Akira consumes coffee and energy drinks, which belong to the category of stimulants. Such drinks have this property largely because they contain caffeine. Caffeine is known for its ability to increase the activity of the central nervous system. This type of stimulant is a natural compound of coffee and tea plants and thus is a very widely available stimulant. Energy drinks are reported to contain caffeine in much more significant amounts than coffee and tea.

Melatonin. Melatonin is a hormone produced in the human brain. It is responsible for sleep and wakefulness patterns. Because Akira is a student, he is likely to use electronic devices, like smartphones and computers, for many hours per day. The wide array of scientific research has connected trouble sleeping to the use of electronic devices because their screens emit blue light. The blue light suppresses the production of melatonin in the brain and can cause sleep disorders like insomnia.  After asking all the necessary questions about Akira's lifestyle and habits his doctor might advise to reducing exposure to the blue light.

Narcolepsy. Narcolepsy is a neurological disorder that is characterized by an inability to stay awake. The medical examination and study that Akira will undergo will help his doctor to identify if Akira is suffering from narcolepsy. Narcolepsy is a rare condition that can be easily mistaken for secondary hypersomnia, which is on the contrary very common. Secondary means that it is a result of the other (primary) condition or disorder, like obesity, sleep apnea or clinical depression. Once Akira’s doctor will run all necessary diagnoses and will identify the cause of Akira’s condition, he will receive a respective treatment.