The correct answer is: Only conclusion I follows.
The statement says that National Aluminium Company has moved India from a position of shortage to self-sufficiency in the metal. This means that India used to import aluminium, but now it can produce enough aluminium for its own needs. However, the statement does not say anything about whether India is currently exporting aluminium or not. Therefore, we cannot conclude that India will soon become a foreign exchange earner.
Conclusion I follows because the statement says that India used to import aluminium, but now it can produce enough aluminium for its own needs. This means that India has become self-sufficient in aluminium.
Conclusion II does not follow because the statement does not say anything about whether India is currently exporting aluminium or not. Therefore, we cannot conclude that India will soon become a foreign exchange earner.