A B, C, and D discuss the weekend outing. A says: B goes, I will definitely go; B says: C goes I will not go; C says: No matter if D goes or I go, D says: At least one of A and B will go, I will go. Which of the following inferences may be correct? ['B and C are gone.', 'A went alone.', 'A. C, and D went.', 'Four people have gone.']