The answer is most likely (c.) the spinal cord
The spinal cord is the spine that connects all parts of the body to the brain. It also transmits sensory neurons to the brain.
Among the answers, the amygdala influenced the emotions the most. It is located near the base of the brain, its function is to link perceptions and thoughts with emotional meaning. Thalamus, on the other hand, regulates the consciousness, sleep, and alertness that may affect the person's emotion. And prefrontal cortex indicates to the person's personality.
One key similarity would be that they all started off as colonial powers ruled by larger power in Europe. Most of these nations gained independence through revolution as well, while a smaller amount gained it by the European state giving the colony independence (canada, Jamaica), Cuba was also technically both (revolution against spanish to be ruled by America, given Independence by America). A big difference is that most of North america was ruled by the British and the French, while South and Central America were settled predominantly by the Spanish and Portuguese. This resulted in huge differences in culture, including language (English/french vs Spanish/Portuguese) and religion (Protestantism vs Catholicism).
