Answer:
(d)cannot tell without more information.
Explanation:
Autarkic economy is a self reliant economy, consuming entirely from its own production.
An autarkic economy maximises its utility when : Its PPF & Social Indifference Curve are tangent to each other.
Their tangency gives utility maximising point with the available resources & technology.
Other options are inapt because: Production on PPF is a necessary but not sufficient condition for social utility maximisation (tangency also needed). Production under PPF reflects under utilisation of resources, cant be utility maximising. Production above PPF is unattainable.