1- Bhilai, Rourkela and Durgapur integrated iron and steel plant were set up during the second plan period.
2- For management of the public sector undertaking SAIL was incorporated in 1973.
3- Ratangiri is the only large integrated iron and steel plant in the western coast.
4- First, port oriented steel plant in India was set up at Vishakhapatnam.
Which of the above is/are correct?