Brief psychotherapy requires far fewer hours and costs far less money than psychoanalysis and so will hopefully prove to be an effective treatment for many of the large amount of people currently seeking therapy.

a. will hopefully prove to be an effective treatment for many of the large amount
b. will prove hopefully to be an effective treatment for many of the large amount
c. hopefully will prove to be an effective treatment for many of the large number
d. will, it is hoped, prove to be an effective treatment for many of the large number
e. will, it is hoped, prove to be an effective treatment for many of the large amount

What is the difference between 'hopefully' and 'it is hoped'?