For how many families, savings is non - negative for each of the years?
This question set is purely based upon observation. That also, very careful observation.
For Verma family, saving is negative in 2007, so we do not need to check for other years.
For Sharma ramily also, saving is negative five in 2007.
For Sinha and Patel family, savings is negative in first year itselt.
For Agrawal Camity, this is zero for 2008, and positive for all the years. Since question is asking for non-negative value, only Agrawal family's data satisfies this condition. Hence option (b) is the answer.