#### Answer

The truth table is already given, and again there is only one case with
a 1 bit in the output. This occurs in the first row and corresponds to the
Boolean expression
$\overline{a} \cdot \overline{b}$
Given this single subexpression, we can proceed immediately to draw the
circuit diagram:
$$continue\ solution\ by\ see\ the\ following\ image:$$

#### Work Step by Step

The truth table is already given, and again there is only one case with
a 1 bit in the output. This occurs in the first row and corresponds to the
Boolean expression
$\overline{a} \cdot \overline{b}$
Given this single subexpression, we can proceed immediately to draw the
circuit diagram: