Which of the following are true with respect to Indian Railways?I. It is the larqest public sector undertakingII. Indian Railway network is the fourth largest in the worldIII. Factories at Kapurthala and Perarnbur manufacture passenger coachesIV. The narrow guage lines are confined to the hilly areas only

• A. , II and III
• B. and II
• C. I, III and IV
• D. , II, III and IV