A. indefinite
B. vague
C. idealistic
D. optimistic
pragmatic : dealing with things sensibly and realistically in a way that is based on practical rather than theoretical considerations.
indefinite : lasting for an unknown or unstated length of time.
vague : of uncertain, indefinite, or unclear character or meaning.
idealistic : characterized by idealism; unrealistically aiming for perfection.
optimistic : hopeful and confident about the future.
Antonym of pragmatic is idealistic