Which of the following statements are correct? 1. The Northern cities of India have in general, an unbalanced sex-ratio. 2. The eastern cities are scattered as against concentration of western cities. 3. There is larger participation of women in the labour force in the south due to small proportion of Christians in the population as also the high literacy rate. 4. Western cities have lower proportion of immigrants from rural areas. Select the correct answer from the codes given below: Codes :