The correct option is
C Define the period of an exponential function
- When a function repeats its values at regular intervals or periods is known as a periodic function.
- The particular interval after which a function repeats its values is called the period of the function.
- The graph of an exponential function is given along.
- The graph depicts that an exponential function is periodic and have a purely imaginary period .
Thus, the period of the exponential function is which is imaginary.
Hence, option (C) is the correct option.