(i) According to Hooke's law within the elastic limit, stress is proportional to the strain. (ii) Shearing strain is defined as angle in radian through which a plane perpendicular to the fixed surface of the cubical body gets turned under the effect of tangential force. (iii) The temporary loss of elastic properties because of the action of repeated alternating deforming force is called elastic fatigue. Hence option (c) is correct.