The output waveform of the given logical circuit for the following inputs $$A$$ and $$B$$ as shown below, is

$$Y = \overline{(\bar{A}) \cdot (\bar{B})}$$

$$Y = \overline{(\bar{A})} + \overline{(\bar{B})}$$

$$Y = A + B$$

An OR gate output drops to low ($$0$$) if and only if both inputs are simultaneously low. Looking at the provided input signals, the only interval where both $$A$$ and $$B$$ sit at the $$0$$ baseline together is the tiny gap between $$t_4$$ and $$t_5$$ (apart from the starting). Hence, Option D is the only graph that fits this.