We need to check for the state CBA → 110 at which we need to clear the inputs (CBA → 000)….
let us represent the output of 2 input gate to be X….
Note : we are passing the complements of C and B to the 2 input GATE….
when C' = 1 and B' = 0 , X should be 1
when C' = 0 and B' = 1 , X should be 1
when C' = 1 and B' = 1 , X should be 1
But only when C' = 0 and B' = 0 , X should be 0 (Since this is the case where C=1 and B=1 and also the clear inputs (active low) are low)
The output represents the OR Gate…
Answer : Option C