The correct answer is: Only argument I is strong.
Argument I is a strong argument because it provides a clear and concise reason why the railways in India should be privatized. The argument states that privatization is the only way to bring in competitiveness and provide better services to the public. This is a valid reason because it is based on the assumption that private companies are more efficient and innovative than public sector enterprises.
Argument II is a weak argument because it does not provide a clear and concise reason why the railways in India should not be privatized. The argument states that privatization will pose a threat to the national security of our country as multinationals will enter into the fray. However, this argument does not explain how privatization will pose a threat to national security. It is also possible that multinational companies can provide better services to the public than public sector enterprises.
Therefore, only argument I is strong.