One-way slab:-  It was pointed out that a ‘one-way’ action may be assumed when the predominant mode of flexure is in one direction alone.

Rectangular slabs which are supported only on two opposite sides by unyielding (wall) supports and are uniformly loaded (uniform along the direction parallel to the supports) provide examples of ideal one-way action.

Two-way slab:- If the uniformly loaded rectangular slab is supported on all four edges, then the deformed surface of the slab will be doubly curved, with the load effects transferred to all four supporting edges. Such action is called a two-way action, involving significant curvatures along with two orthogonal directions.

Torsion in two-way slab

In general, twisting moments develop in addition to bending moments in a two-way slab element except when the element is oriented along the principal curvatures. These twisting moments can become significant at points along the slab diagonals.

All condition given in the statement is fulfilled by a one-way slab as discussed above hence statement 1 is correct.

In two ways slab, both twisting and bending moments are generated hence statement 2 is also correct