A man has 7 relative, 4 of them ladies and 3 gentleman. his wife also have 7 relatives. 3 of them ladies and 4 gentlemen, They invite for a dinner partly 3 laddies and 3 gentlemen so that there are 3 of the men's relative and 3 of the wife's relative. The number of ways of invitation is _______
(a) 854
(b) 585
(c) 485
(d) 548
