Solution CRS.M10 Robert Beezer
Any vector from $\complex{3}$ will lead to a consistent system, and therefore there is no vector that will lead to an inconsistent system.

How do we convince ourselves of this? First, row-reduce $E$, \begin{equation*} E\rref \begin{bmatrix} \leading{1} & 0 & 0 & 1\\ 0 & \leading{1} & 0 & 1\\ 0 & 0 & \leading{1} & 1 \end{bmatrix} \end{equation*} If we augment $E$ with any vector of constants, and row-reduce the augmented matrix, we will never find a pivot column in the final column, so by Theorem RCLS the system will always be consistent.

Said another way, the column space of $E$ is all of $\complex{3}$, $\csp{E}=\complex{3}$. So by Theorem CSCS any vector of constants will create a consistent system (and none will create an inconsistent system).