Which of the following can be considered as a cause of the U$.$S$.$ financial crisis?

I. The enormous growth in non$-$conforming home mortgage loans

II$.$ The use of complex credit derivatives backed by home mortgages

III. Inadequate regulation and oversight, particularly of the "shadow banking" system

Question $45$Select one:

a$.$

I only

b$.$

I and II only

c$.$

I and III only

d$.$

I, II$,$ and III