This is heavily disputed, and honestly, it varies on a person-by-person basis. Some people are visual learners (so it's effective for them to use videos and pictures to help them study), some prefer being hands-on, etc...
Generally though, I'd say the most effective method that works for most people is through visceralisation. This is the process of associating concepts, words. phrases etc. with your different senses (sound, touch, images...). You can read up more on it by searching up "visceralisation for studying".
The correct answer would be D
Cardiovascular disease would be the most likely as the oxygen taken in is polluted and enters the blood stream. Thus as it travels to the heart and throughout your body you risk disease.
Helium , neon , and Aragon
