Muscular Endurance i believe.
I believe the answer to your question is oligodendrocytes.
C. Delivers more oxygen to the body
Weak bases, just like weak acids, dissociate slowly when dissolved with water. An Arrhenius acid is any substance that ionizes when it dissolves in water to give the H+, or hydrogen, ion. An Arrhenius base is any substance that gives the OH-, or hydroxide, ion when it dissolves in water.
Larry is taking a walk in the park. The pollen in the air makes him sneeze constantly. The line of defense that is his immune system exhibiting is that of "(A) first line of defense." There are only 3 lines of defense in the immune system. The first line of defense are a combination of physical and chemical barriers that prevent all types of foreign agents from penetrating the outer layer of the body. In this case, it is the nasal cavity.