The correct answer is D. Boltzmann’s equations.
Boltzmann’s equations are a set of partial differential equations that describe the statistical behavior of a system of particles. They are used to calculate the distribution function of particles in a system, which is the probability of finding a particle with a given momentum and position.
Maxwell’s equations are a set of four partial differential equations that describe the classical electromagnetic field. They are used to calculate the electric and magnetic fields in a system, and are the basis of classical electromagnetism.
Peterman equations are a set of equations that describe the evolution of a plasma. They are used to calculate the density, temperature, and pressure of a plasma, and are the basis of plasma physics.
Allen Cahn equations are a set of equations that describe the evolution of a phase boundary. They are used to calculate the position of the phase boundary, and are the basis of phase field theory.
Boltzmann’s equations are the most appropriate equation to calculate MFD because they describe the statistical behavior of a system of particles, which is what MFD is.