A protein has n ligand binding sites and exhibits infinite cooperativity for ligand binding (fully cooperative). Which of the following is correct about this protein?

a) has a Hill coefficient (nH) equal to 0

b) it can only exist in either the free or the fully liganded states

c) has a Hill coefficient equal to n

d) the fractional saturation curve is linear

e) has a Hill coefficient (nH) equal to 1.0

Please give a detailed explanation