The logic expression for the output of the circuit shown in figure below is:
$\overline{AC} + \overline{BC} +CD$
$A\overline{C} + B\overline{C} + CD$
$ABC +\overline {C}\; \overline{D}$
$\overline{A}\; \overline{B} + \overline{B}\; \overline{C} +CD$
Better to simplify the circuit: