Step 1: Using deBroglie relation.
The deBroglie wavelength \( \lambda \) of a particle is given by
\[
\lambda = \frac{h}{\sqrt{2mEK}}
\]
where \( m \) is the mass and \( EK \) is the kinetic energy.
Step 2: Analyzing the options.
Since the kinetic energy is the same for both, the ratio of wavelengths depends on the masses of the particles. Hence,
\[
\frac{\lambda_e}{\lambda_p} = \frac{m_p}{m_e}
\]
Step 3: Conclusion.
Therefore, the correct answer is option (D).
Final Answer:
\[
\boxed{\frac{m_e}{m_p}}
\]