Read the following statements relating to flexure of reinforced concrete beams :

I. In over-reinforced sections, the failure strain in concrete reaches earlier than the yield strain in steel.

II. In under-reinforced sections, steel reaches yielding at a load lower than the load at which the concrete reaches failure strata.

III. Over-reinforced beams are recommended in practice as compared to the under-reinforced beams.

IV. In balanced sections, the concrete reaches failure strain earlier than the yield strain in tensile steel.

Each of the above statements is either True or False.

Which one of the following combinations is correct?

Maximum strain at the level of compression steel for a rectangular section having effective cover to compression steel as $$d'$$ and neutral axis depth from compression face $${X_u}$$ is