Is a cold and b is warm? Please help

Which ocean zone has the most abundant primary producer and why a) the abyssopelagic zone ,du to the absence of light and cold water temperatureb) the bathypelagic zone, due to the absence of light and cold water temperaturec) the mesopelagic zone ,due to uts high light availability and warm water temperature d) the epipelagic zone,due to its high light availability and warm water temperature

How is electrolysis most commonly used to produce an energy source? a - splitting water molecules produces oxygen, which organisms breathe to fuel their bodies. b - splitting water molecules produces hydrogen gas, which is used to power machines through hydrogen fuel cells. c - splitting carbon dioxide molecules produces coal, a form of carbon that can be burned to produce heat. d - splitting carbon dioxide molecules produces natural gas, which can be burned to generate electricity in power plants.

Which of the following represents the balanced reduction half-reaction from the redox reaction? (2 points) pb + pd(no3)2 yields pb(no3)2 + pd pb yields pd2+ + e- pd2+ + 2e- yields pd pb + e- yields pb 2 pd2+ + 4 e- yields 2 pd