def last(a)

if not a;

return None

elif len(a) == 1

return a[0]

else:

return __________

Which recursive call completes the implementation so that when passed a non empty list as the initial argument, the last element in the list is returned?

A. last (a[0])

B. last (a[1:])

C. last(a[:-1)

D. last (a[1:-1])

I believe it is C as it returns the last element but D is also confusing me as it could also return the last element?