ANS:B - two

Stress and strain are related by two elastic constants for a linearly elastic, homogeneous, and isotropic material. These two elastic constants are typically referred to as Young's modulus (or modulus of elasticity) and Poisson's ratio. Young's modulus represents the ratio of stress to strain in the direction of the applied force, while Poisson's ratio represents the ratio of lateral strain to longitudinal strain when a material is subjected to uniaxial stress. Therefore, the correct option is: two