GEB FL 390 is not available due traffic alternative is FL350 advise what does this ATC instruction mean?

A、GEB FL390 can’t be provided due traffic you can choose FL350 instead please tell me your intension
B、GEB FL390 can’t be accepted fly to the alternate FL350 advise
C、GEB FL390 is not available due traffic, descent to FL350 via alternative level
D、GEB you can fly FL390 due traffic, tell me when you fly to FL350 via alternative level