What is the answer of this question

Use examples from the article to explain one positive and one negative effect that chemistry has had on society.

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

Avariable that is not being directly tested during an experiment should be