DIRECTIONS: On the basis of following diagram / picture answer the questions given below: In the circuit below, which switch should be left open and which switch should be left closed so that only bulb Y lights up? Switch A Switch B Switch C Switch D

• A. Closed             Closed             Open               Open  
• B. Closed             Open               Open               Closed
• C. Open               Open               Closed             Closed
• D. Open               Closed             Closed             Open