The system of equations $$ \begin{aligned} &x+y+z=6 \\ &x+4 y+6 z=20 \\ &x+4 y+\lambda z=\mu \end{aligned} $$ has **NO** solution for values of $\lambda$ and $\mu$ given by

- $\lambda=6, \mu=20$
- $\lambda=6, \mu \neq 20$
- $\lambda \neq 6, \mu=20$
- $\lambda \neq 6, \mu \neq 20$