What the hell is this a answer
The circulatory system - hemoglobin in the blood transports oxygen :)
B. Soil Contamination
All the other answers are talking about clean and pure things while this answer is the only negative one. So B is your answer.
2 examples -
1.) in italy, ( limone ) a unique mutation protects them from developing atherosclerosis,
2.)theres mutation in bacteria too, this mutation allows bacteria to survive in the presence of antibiotic drugs, leading to the evolution of antibiotic-resistant strains of bacteria.
