Consider a logic circuit shown in figure below. The functions $f_1, f_2 \text{ and } f$ (in canonical sum of products form in decimal notation) are :
$f_1 (w, x, y, z) = \sum 8, 9, 10$
$f_2 (w, x, y, z) = \sum 7, 8, 12, 13, 14, 15$
$f (w, x, y, z) = \sum 8, 9$
The function $f_3$ is
- $\sum 9, 10$
-
$\sum 9$
-
$\sum 1, 8, 9$
-
$\sum 8, 10, 15$