The correct answer is: Only I and II are strong.
Argument I is strong because it is based on the fact that Lok Adalats and mobile courts can help to grant speedy justice to the masses. This is a valid reason to encourage the system of Lok Adalats and mobile courts in India.
Argument II is also strong because it is based on the fact that the dispensing of minor cases at this level would reduce the burden on the higher courts. This is another valid reason to encourage the system of Lok Adalats and mobile courts in India.
Argument III is weak because it is based on the assumption that these courts are usually partial in justice. This is an unsubstantiated assumption and there is no evidence to support it.
Therefore, only arguments I and II are strong.