Correct Answer - B
The truth table of the circuit is given as
`|(A,B,C,X=bar(AB),Y=bar(BC),Z=bar(X+Y)),(0,0,0,1,1,0),(1,0,0,1,1,0),(0,0,1,1,1,0),(1,0,1,1,1,0),(0,1,0,1,1,0),(1,1,0,0,1,0),(1,1,1,0,0,1)|`
Output `Z` of single three input gate is that ot `AND` gate.