Which of the Following Statements Is CORRECT

Which of the following statements is CORRECT?

A) The internal pH of the cells of an organism is usually the same as the pH of the external environment.
B) The internal pH of the cells of an organism may be quite different to the pH of the external environment.
C) Regardless of the internal pH of their cells, most living organisms can only survive within a narrow range of environmental pH.
D) Regardless of the pH of the environment, most living organisms will not survive if the internal pH of their cells fluctuates.
E) The internal pH of a muscle cell may become more basic during exercise.