In Town X, the water has heavy metal M. In Town Y, the water has heavy metal N. Residents of both towns drink the water with no issues.
However, in Town Z, the water has both metal M and N; and the residents have long-term kidney damage. What conclusion can be made about the two metals?
O More metals cause acute effects but not chronic effects.
O The first metal causes an acute effect compared to the other
O The heavy metals have a synergistic relationship when combined
The heavy metals have an antagonistic relationship when combined.