Correct Answer: (d) Soviet Union
Solution:Bokaro Steel Plant-the fourth integrated plant in the Public Sector-started taking shape in 1965 in collaboration with the Soviet Union (USSR). It was originally incorporated as a limited company on 29th January, 1964, and was later merged with SAIL., first as a subsidiary and then as a unit, through the Public Sector Iron & Steel Companies (Restructuring & Miscellaneous Provisions) Act 1978. The construction work started on 6th April, 1968 and its first blast furnace started on 2nd October, 1972.