What Grade Is This Fuseki / HolIgor's opinion

What's next?  

• They are not shodan level. I am about the level of a Japanese shodan. I know how those guys play.
• As usual there are some hints in the way the question was asked, so one arrives at the answer not because the problem is solved but using some side criteria. If we are asked to show the next move then everything here is reasonable, which means they are high level dans.
• I have no clue how high level players think, especially in fuseki, which is my weakest point. To continue the strange play I would propose a.

--HolIgor