Respuesta :
Answer:
A. 3 x 10-12
Explanation:
Generally, the parts-per notation is used to represent very small concentration without any specific unit.
Parts per million is notated as [tex]10^{-6}[/tex]
Parts per billion is notated as [tex]10^{-9}[/tex]
Parts per trillion is notated as [tex]10^{-12}[/tex]
Hence, 3 parts per trillion will be written as 3 x [tex]10^{-12}[/tex]
The correct option is A.