The following figure shows a logic gate circuit with two inputs $A$ and $B$ and the output $Y.$ The voltage waveforms of $A, B$ and the output $Y$ are as given in the diagram. The logic gate is $:-$

• A
  $\text{NOR}$ gate
• B
  $\text{OR}$ gate
• C
  $\text{AND}$ gate
• D
  $\text{NAND}$ gate