When Partners in a Romantic Relationship Break Up with Each

When partners in a romantic relationship break up with each other, they often plan to remain friends. What happens in reality?

A) Most do not remain friends. But they say this (and they often try to remain friends) because they are reluctant to break social bonds.
B) Most do not remain friends, and never, in fact, expect to remain friends. They say this only to be polite.
C) Most do remain friends despite thinking that they will not.
D) Most do remain friends, though such friendships are harder to sustain than other friendships.