B. Salmon envolved before kangaroos
the predominant pollutants include nitrogen oxides, particularly nitric oxide (NO) and nitrogen dioxide (NO2), and volatile organic compounds.
The sign of lead poisoning in children would be impaired development.
Lead is very toxic to the brain, so lead poisoning will be especially dangerous in children when the brain is developing at a high rate. Damage to the brain will cause the children to have an impaired development and growth, gastrointestinal pain, or neurological issue like seizure.
