A, let the inclination angle of the inclined plane be θ, the height be h, and the length of the inclined plane be l,

Work done by friction W=-μmgcosθ? L=？ μmgcosθ？ hsinθ=？ μmghcotθ, so the greater the inclination angle, the smaller the work done by friction and the smaller the work done by overcoming friction, so A is wrong;

B, the length of inclined plane L=hsinθ, and the acceleration is equal. According to v=2ax, the longer the slope length, the greater the final speed. According to the kinetic energy theorem, the work done by the resultant force is equal to the change of kinetic energy, so the longer the inclined plane, the greater the work done by the resultant force, that is, the more work done by the resultant force with a small inclination angle, so B is wrong;

C, gravity work is only related to the height difference, the height is equal, so the work to overcome gravity is equal, so C is wrong;

D: According to Newton's second law, F-mgsinθ-μmgcosθ=ma.

The solution is: F=mgsinθ+μmgcosθ+ma.

So the work done by F is: w = FL = (mgsinθ+μ gcos θ+Ma) hsinθ = mgh+μ ghcot θ+Mahsin θ.

Because m, h, a and μ are equal, the smaller θ is, the greater W is, so D is correct.

Therefore, choose: d.