The Substance Indicated by "A" in the Figure Shown Here

question 18

Multiple Choice

The substance indicated by "A" in the figure shown here

• A) is composed of formed elements, mostly platelets.
• B) is a fluid and contains nutrients, gases, proteins, and ions.
• C) is composed of formed elements, mostly white blood cells.
• D) is 100% water.
• E) carries most of the oxygen in the blood.

---

Definitions:

Skeletal Adaptations

Changes in the skeletal structure that occur over time to help an organism better survive in its environment.

Four-Legged Walkers

Animals that use all four limbs to support their movement across a substrate, showcasing a quadrupedal mode of locomotion.

Land Dwellers

Organisms that live predominantly or entirely on land as opposed to in the water or air.

Notochord

A flexible rod-like structure in the embryos of all chordates, providing skeletal support and defining the primitive axis of the body.