Explanation:

- The Census of India 2011 tracked various demographic statistics, including estimates related to the mortality rate of children under five years old.

- Option 1: 34 – This option is not the estimated national mortality rate from Census 2011. The number reflects lower mortality but is not correct for 2011 data.

- Option 2: 55 – This is indeed the correct estimate according to the Census of India 2011 for the under-five mortality rate, reflecting the challenges in child healthcare during that period.

- Option 3: 76 – This figure is too high for the 2011 estimate and does not accurately represent data from that census period.

- Option 4: 13 – This is significantly low and not representative of the status during 2011 for children under five.