B . Excessive commercial fishing
Reason: the other options are good things this is the only bad thing
<span>reaction of CO2 and H2O</span>
████████▀▀▀████
████████────▀██
████████──█▄──█
███▀▀▀██──█████
█▀──▄▄██──█████
█──█████──█████
█▄──▀▀▀──▄█████
███▄▄▄▄▄███████
Frogs reproduce by a special kind of embrace called "amplexus" which is an external fertilization that does not occur inside the female's body.
During mating (amplexus), the male frog grasps the female frog's trunk with his forelimbs.
The female frog discharges eggs into the water and then the male frog sheds the sperms over those eggs.