An isotropic elastic material is characterized by
(a) Two independent moduli of elasticity along two mutually perpendicular directions.
(b) Two independent moduli of elasticity along two mutually perpendicular directions and Poissons’s ratio.
(c) A modules of elasticity, a modulus of rigidity and Poission’s ration.
(d) Any two out of a modulus of elasticity, a modulus o rigidity and Poisson’s ratio.