The output of a logic gate is low when any one of the inputs is high. Which gate does this statement describe?

If $a, b, c, d$ are inputs to a gate and $x$ is its output,then,as per the following time graph,the gate is

For the logic gates shown below,the correct output is

Which of the following represents the $NAND$ gate?

The following figure shows a logic gate circuit with two inputs $A$ and $B$ and the output $C$. The voltage waveforms of $A$,$B$,and $C$ are as shown below. The logic circuit gate is

In a digital circuit for three input signals $(A, B, \text{ and } C)$, the final output $(Y)$ should be such that for inputs:
| $A$ | $B$ | $C$ |
|---|---|---|
| $0$ | $0$ | $0$ |
| $0$ | $0$ | $1$ |
| $0$ | $1$ | $0$ |
the output $(Y)$ should be $0$, and for all other cases, it should be $1$. Which of the following digital circuits will give such output?