Answer: Crystalline solid
Explanation: Crystalline solids are those in which the constituents are arranged in the systematic order. These constituents are held together by the strong forces of attraction.
There is a regular pattern of the molecules which is repeated uniformly through the crystal lattice.
Thus when salt is being examined under microscope, then these similar pattern would have been retrived. Thus the magnified image of the salt can be best described as the crystalline solid.