Science P6 MBS 2018 SA1 Q28

Study the circuit diagram below.Which of the following shows the correct switches being closed when only B1 and B6 are lit up?
optionsSwitch closed
S1S2S3S4
A✔︎✔︎✔︎
B✔︎✔︎
C✔︎✔︎✔︎
D✔︎✔︎