Which of the following animals have a central nervous system? Those that are cephalized Those that are radially symmetrical Those that are slow moving and sessile Those that are cephalized and radially symmetrical None of the above

The correct answer is: A) Those that are cephalized.

Explanation:

The Central Nervous System is only present in animals that are cephalized, capable of moving, and have bilateral symmetry.

Cephalized animals have a proper region in their front end in which the mouth, the sensory organs and the nerve ganglia concentrate and form a "head".

An animal with bilateral symmetry has a single plane of symmetry (the sagittal plane) which divides the body into two halves: one left and one right.

Animals that are radially symmetrical exhibit a pattern around their central axis that repeats itself up to 8 times. A good example of a radially symmetrical animal is a starfish.