I think it is the 3rd answer choice.
High levels of dissolved oxygen
Answer:
Porosity
Explanation:
Porosity is defined as the total percentage of pore spaces that are present within a rock. These spaces are found between the rock particles and fractures and are mostly filled with fluid mixture or water. It is the ratio between the total pore space in a rock to the total volume of the rock. It is mainly calculated in terms of percentage.
Porosity is directly affected by sorting. Well-sorted rocks indicate high porosity but poorly-sorted rocks indicate low porosity. Some of the examples of rocks exhibiting high porosity are limestone, shale, and sandstone. Rocks with low porosity include granite and mudstone.
Doldrums is the calm area near the equator.
