The Answer is A) Outputs the sum of the present and the previous bits of the input.
Before taking any input lets name the bits of input we have 3 bit input it have 1st, 2nd, and 3rd bit.
Present bit = Iteration Number say nth then present bit will be n
Previous bit = the previous iteration number i.e. n-1 then previous bit will be (n-1)th bit,
for 1st bit previous bit will be nothing.
Example Input bit is 000 // 1st =0, 2nd = 0, 3rd = 0
At first iteration when we are A on 0 go to A -> OP 00 // As 0 + no previous bit is 0 only,
At second iteration when we are A on 0 go to A -> OP 00 // As 0 + 0(prev) is 0 only,
At third iteration when we are A on 0 go to A -> OP 00 // As 0 + 0(prev) is 0 only,
Example input is is 111 // 1st =1, 2nd = 1, 3rd = 1
At first iteration when we are A on 1 go to B -> OP 01 // As 1 + no previous bit is 01 only,
At second iteration when we are B on 1 go to B -> OP 10 // As 1+1(prev) is 10 only,
At third iteration when we are B on 1 go to B -> OP 10 // As 1 + 1(prev) is 10 only,
Example input bit is 101
// 1st =1, 2nd = 0, 3rd = 1
At first iteration when we are A on 1 go to B -> OP 01 // As 1 + no previous bit is 01 only,
At second iteration when we are B on 0 go to A -> OP 01 // As 0 + 1(prev) is 01 only,
At third iteration when we are A on 1 go to B -> OP 01 // As 1 + 0(prev) is 01 only,
Similarly take other example also for more understanding and you will get ans
A) Outputs the sum of the present and the previous bits of the input.
