Which of the following must be true for the following code to execute without error? There may be more than one correct answer.

for x in C: print(x) 

Answer choices:

C has an __iter__() method.

C possesses an instance variable i which represents the current state of iteration.

C is a container.

The code len(C) executes without error.

C has a __next__() method.

The output of iter(C) has a __next__() method.