Which of the following expressions may be used to correctly describe the temperature (T) variation of the intrinsic carrier density (ni) of a semiconductor?

• A. ni(T) = (A/T) exp (- E8/kT2)
• B. ni(T) = A (- E8/2kT)10
• C. ni(T) = A exp (- E8/2kT2)
• D. ni(T) = AT3/2 exp (-E8/2kT)