ANS:A - True

When getting the Thevenin voltage the RL is deemed as open, and since it is open then no current would flow into the 800-ohm resistor making the circuit a series connection between the 400, 200 and 600-ohm resistors.

The Thevenin voltage is equal to the voltage drop in the 600-ohm resistor since the connection is in series we can use the voltage divider formula Vth = (12V) (600) / (600+400+200) = 6V.