This function returns the next element from the iterator. If the iterator is exhausted, a StopIteration exception will be raised. You can also pass a default value to this function, which will be returned instead of raising a StopIteration exception. Which built-in function does this description apply to?

This function returns the next element from the iterator. If the iterator is exhausted, a StopIteration exception will be raised. You can also pass a default value to this function, which will be returned instead of raising a StopIteration exception.
Which built-in function does this description apply to?
a. iter()
b. next()
c. gen()
d. func()