Consider the following statements:
(P) Hardness is the resistance of a material to indentation.
(Q) Elastic modulus is a measure of ductility
(R)Deflection depends on stiffness
(S) The total area under the stress-strain curve is a measure of resilience.
Among the above statements, the correct ones are
(a) P and Q only (b) Q and S only
(c) P and R only (d) R and S only