Explanation:

- The Rolling Plan was introduced in India to adapt more flexibly to socio-economic changes rather than sticking to a fixed plan.

- Option 1: Fourth and Fifth Five-Year Plans were from 1969-1974 and 1974-1979. The Rolling Plan wasn't implemented during these plans.

- Option 2: Sixth and Seventh Five-Year Plans spanned from 1980-1985 and 1985-1990. The Rolling Plan wasn't active here.

- Option 3: Second and Third Plans covered 1956-1961 and 1961-1966. Rolling Plan wasn't relevant here either.

- Option 4: Fifth and Sixth Five-Year Plans occurred between 1974-1979 and 1980-1985. The Rolling Plan was implemented between these plans, specifically from 1978-1980.