Answer:
(I don't see a chart but I'll give it a guess based on the info I have)
1. C. Sugar cane. Though all other options are true to some extent.
2. B. They all have a warm/tropical climate.
3. D. Brazil.
4. B most likely - can't guarantee.
5. Again, no chart, but probably D.
6. E? Or F is also a possibility.
I'm winging it here, so correct me if I'm wrong.
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.
