That is such an inappropriate question to ask of anyone. Boy some need lessons in tact and social graces. And you just joined to ask such a tacky question? WTF?
I guess you gotta try them all before coming to a scientific conclusion

So stop asking and get busy because you have your work cut out for you!
Where I used to work, someone WHO CAME TO DROP OFF THEIR KID asked me that (like I would know the answer). My reply to him:
"dunno, why don't you ask your wife!"