A 3-line to 8-line decoder is connected as shown, where x, y, and z are
inputs (z is the least significant input digit) and F is an output.
F = 1 when
3 is CORRECT. Examining the truth table for output F = SUM m(3,5,6), it may be seen that F will equal a logical 1 when any 1 out of the 3 inputs are logical 0.