A tree has been used to create a prefix code. Which of the

following would be possible in a scheme like this?

Three of the letters in the tree use these codes:

a: $0$

b: $10110$

c: $110$

Three of the letters in the tree use these codes:

a: $0$

b: $100$

c: $011$

Three of the letters in the tree use these codes:

a: $0$

b: $10110$

c: $101$