Step 1: Understanding the ground state energy.
For a quantum harmonic oscillator, the ground state energy for spin-less fermions is determined by the Pauli exclusion principle. The total energy depends on the number of available states. For fermions, the energy of the system is given by \( E_0 = \frac{25}{2} \hbar \omega \).
Step 2: Conclusion.
Thus, the correct answer is option (C).