72. The relation between

The relation between λ,ηand K for a elastic material is

(a)  (1/η)=(1/3λ)+(1/9k)                                  (b)  (1/k)=(1/3λ)+(1/9η)

(c)  (1/λ)=(1/3k)+(1/9η)                                    (d)  (1/λ)=(1/3η)+(1/9k)

Answer-d