Eurodollar perfect hedge

[h21]

Hi all, on question 11 of of reading 48, here are two options listed in the question about eurodollar
Convexity bias allows the construction of a perfect hedge/ Backwardation bias allows the construction of a perfect hedge.
This just doesnt make sense to me at all, can someone please help me understand what they mean?also with the whole eurodollar perfect hedge issue, i am so confused
Thanks

 

[h21]

bump anyone?

 

[S2000magician]

You cannot construct a perfect Eurodollar hedge because the discount rate (LIBOR) for Eurodollar futures isn’t known until the expiration of the futures contract.
Nothing changes that.