LOGIC CIRCUIT 3

You  are given the following logic circuit.

All the gates are NAND

gates, that is  

( NOT (AND)) gates

Assuming  that 

(TU1)   for M1

·        

Y=1

·         D=1

·        

E=1

Your task  is determining how many  combinations of A,B,C,   values  are possible?

(hint:   Try 

to work the solution backward, starting with last NAND gate  that outputs Y

Determine all the

possible combinations of A,B,C, that satisfy  

( Y=1,  D=1, E=1). You must  select all that apply   amongst  the following alternatives