American & British leaders & buissnessmen wanted to ship goods quickly & cheeply between the Atlantic & Pacific Coasts
Actually, I am pretty certain that all of the options are common type of volunteering. I feel that the question is suggesting that the educational activities are not typically done as volunteering in the developed world, but in the developing world, educational volunteering is very common (see for example the organisation "teach for [name of country]- operating both in developed and developing world.
Alzheimer's <span>disease is the most common cause of dementia</span>
