Water waves

The above diagram shows water waves generated by two wave sources $S_1$ and $S_2$ with wave length $\lambda$ at a particular instant. Which of the following statements is NOT correct?

Full line and dotted line in the diagram represent the crest and trough, respectively, of the waves.

a) The distance between $S_1$ and $S_2$ is $2\lambda.$
b) The path difference of the two waves to the position $A$ is $\displaystyle \frac{\lambda}{2}.$
c) The phases of wave at the positions $B$ and $C$ are the same.