Question $3$

Given the following circuit, we suspect that $a$ is stuck at $1.$ Which statements below are correct?

We need to force $a$ to be $1$ in order to test whether $a$ is really stuck at $1.$

$b$ and w $5$ must both be set to $0$ so that $e$ can be forced to $0$ in order to test whether $a$ is stuck at $1.$

$d$ needs to be forced to be $0$ so that the effect of a can be propagated to the output.

e needs to be forced to be $1$ so that the effect of a can be propagated to the output.