For a flow, the velocity field and variation in density is given as, $$\bar{V}=(10X+3Y+2Z)\hat{i}+(12X+4Y+5Z)\hat{j}+(8X+7Y+\lambda Z)\hat{k}$$ and $$\rho = \rho_0 e^{-3t}$$ respectively. What is the value of $$\lambda$$, if the mass is conserved ?

A

-11

B

-10

C

10

D

11