$V_{CC}$ is Voltage Common Collector, generally represents the Higher Voltage with respect to $GND$ (Ground)
$GND$ (Ground) is usually a reference point ( $0V$) for a electronic circuits, and in general $Vcc$ is taken as $+5V.$
So, due to higher voltage w.r.t Ground, $V_{CC} = 1$
So, $I_{1}$ and $I_{2}$ is connected with $1$
So, First MUX output will be: $U’V + UV’ $ and this is the Input of Second MUX’s $I_{0}$ and $I_{1}$
Now, $F\ (U, V, W, X) = (U’V + UV’). W’X’ + (U’V + UV’). W’X $
$= (U’V + UV’).( W’X’ + W’X) $
$= (U’V + UV’).W’$
[ Note $:$ $I_{0} , I_{3}$ MUX-1 and $I_{2} , I_{3}$ are connected with Ground i.e Voltage 0, so we didn’t include those in calculation.]
$Ans: Option \ C$