Stagnant, shallow areas of water-saturated soil, where the rate of photosynthesis is low, are best characterized as:.

The correct answer is - bogs.

Explanation:

Bogs or boglands is a wetland that is made up of dead organic matter such as dead plants or parts of the plants like mosses, majority time it is a thick carpet of sphagnum moss. All these form spongy peat which is stagnant.

Most of the water present in this wetland comes from rainfall instead of runoff or streams from the groundwater which makes it a wetland with a shallow area of water-saturated soil. This wetland is known for its less photosynthesis.

answer and explanation;

volcanic rocks are igneous rocks which form from lava, molten rock which has been thrust out of a volcano onto the surface of a rocky body such as an asteroid, planet, or dwarf planet.  

plutonic rocks are igneous rocks which form from subterranean chambers of molten rock or magma. plutonic rocks make up the base of continental crust as well as oceanic crust. their slow rate of formation causes them to be coarse grained since there is plenty of time for large crystals to form before the magma solidifies into rock.

the textural difference is that plutonic rocks are more coarse grained than volcanic rocks. plutonic rocks are coarse grained while volcanic are fine grained ; glassey or fragmental. since fine and coarse are adjectives the decision as to whether a rock is fine or coarse grained is generally made on the bases of whether or not the individual crystals can be seen in most if the rock.