Which ocean ecosystem has low productivity due to low light penetration

Is there multiple choice? It would be the deepest part of the ocean... I believe it’s called the aphotic or “midnight zone”

Very hard to understand

Glucose, also called grape sugar, blood sugar or corn sugar, is among the simplest and one of the primary naturally occurring sugars. produced naturally by plants as the primary photosynthesis product, it is heavily used by living beings as a main energy source and is necessary for cellular respiration. chemically, it is a monosaccharide carbohydrate and serves as a building block for complex sugars like starch.