The output of a 2-input logic gate goes high only when both inputs are low, else it remains low. Which gate it is?

Correct option is C

NOR gate:
 This is also a basic digital logic gate, and it implements logical NOR.
 This means it gives an output of true or '1' only when all its inputs are false or ' 0 '. Conversely, if any of its inputs are ' 1 ', then the output is ' 0 '.
 It's essentially the inverse of the OR gate.
 NOR gate means "not an OR gate" hence the output of this logic gate is just the reverse of that of an OR gate.
 Hence the NOR gate is the inverse of an OR gate, and its circuit is produced by connecting an OR gate to a NOT gate.