Which of the following maintains the patency (openness) of the trachea? a. surface tension of water b. surfactant production c. C-shaped cartilage rings d. pseudostratified ciliated epithelium

The correct option is C) C-shaped cartilage rings

Explanation:

The trachea is commonly known as the wind-pipe. The trachea can be described as about a 4 inch long passage from which the air travels into the bronchi and lungs. The pathway of the trachea is kept open by C- shaped cartilages which are lined all over in the trachea. The C-shaped cartilages protects as well as maintain the shape of the wind-pipe. The rigidity of the trachea arises from the C-shaped cartilages.

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.