I believe the answer to this is A.
Answer:
storm runoff
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Isotopes are variants of a particular chemical element which differ in neutron number, and consequently in nucleon number. All isotopes of a given element have the same number of protons but different numbers of neutrons in each atom.
The term isotope is formed from the Greek roots isos ("equal") and topos ("place"), meaning "the same place".
Answer:
2,4,4-trimethyl-2-pentene yields mixture of
and 
Explanation:
In ozonolysis (hydrolysis step involve a reducing agent such as Zn,
etc.), a pi bond is broken to form ketone/aldehyde.
Ketone is formed from di-substituted side of double bond and aldehyde is formed from mono-substituted side of double bond.
Ozoznolysis involves two consecutive steps : (1) formation of ozonide, (2) hydrolysis of ozonide.
Hydrolysis can be done with/without using reducing agent. Carboxylic acid/carbon dioxide/ketone is produced when hydrolysis is done without using reducing agent.
Here, 2,4,4-trimethyl-2-pentene yields mixture of
and 
Reaction steps are shown below.