During which period did the Congress dominance reflect both at the national and the state level?

1952-1967

The correct answer is Option (1) → 1952-1967

The Congress dominance at both national and state levels was most visible in the period 1952–1967, covering the first three general elections where Congress secured overwhelming majorities across India.

The dominance began to be challenged in the 1967 general election. While the Congress party managed to retain power at the center, its majority was significantly reduced. More importantly, it lost power in nine states, signaling the end of its unchallenged dominance at the state level. This period marked a major shift in Indian politics, moving away from a single-party dominant system towards a more competitive and multi-party political landscape.