Which of the following is an example of a suspension?

A. 100-fold more: A 100-fold difference corresponds to a change of 2 pH units, but the pH difference here is only 1 unit (from 7 to 6).

B. 10-fold fewer: A lower pH indicates higher hydrogen ion concentration, not fewer.

C. 100-fold fewer: This also suggests a lower hydrogen ion concentration, which contradicts the fact that a pH of 6 is more acidic than neutral water.

D. 10-fold more: pH is a logarithmic scale, so each unit change represents a tenfold change in hydrogen ion concentration. A pH of 6 has ten times more H⁺ ions than neutral water at pH 7.

A. Dorsal: The dorsal body cavity protects the central nervous system and is subdivided into the cranial cavity, which encloses the brain, and the vertebral cavity, which encloses the spinal cord. Together, these cavities provide rigid protection by surrounding nervous tissue with bone.

B. Ventral: The ventral cavity contains organs such as the lungs, heart, and abdominal viscera. It is not the primary cavity responsible for protecting the nervous system, as it mainly houses thoracic and abdominopelvic organs.

C. Vertebral: The vertebral cavity specifically encloses and protects the spinal cord. While it is part of the system that safeguards the nervous system, it is only one subdivision of the dorsal cavity rather than the overall cavity protecting the nervous system.

D. Thoracic: The thoracic cavity lies within the ventral body cavity and contains the lungs and heart. It is not associated with protection of the brain or spinal cord, so it does not serve the role of safeguarding the nervous system.

E. Cranial cavity: The cranial cavity encases and protects the brain. Like the vertebral cavity, it is part of the dorsal cavity, but it represents only one subdivision rather than the complete system of protection for the nervous system.