This question checks the base years used to calculate two major Indian stock market indices.
1980-81 and 1990: Not correct. These are not the base years fixed for either index.
1990-91 and 2000: Not correct. 1990-91 is not the Sensex base year, and Nifty was not based in 2000.
1978-79 and 1995: Correct. The BSE Sensex uses 1978-79 as its base year with a base value of 100. The Nifty 50, launched by NSE, uses 1995 as its base year with a base value of 1000.
2000-01 and 2004: Not correct. Neither index uses these years as its base.