Which of the following statements is TRUE?
A) It is necessary to have a nervous system to sense and respond to the environment.
B) All animals have a nervous system and it is necessary to have a nervous system to sense and respond to the environment, but not all animals sense and respond to the environment.
C) All animals have a nervous system, all animals sense and respond to the environment, and it is necessary to have a nervous system to sense and respond to the environment.
D) All animals sense and respond to the environment. All animals have a nervous system.