Step 1: Define population density.
Population density is the number of people living per square kilometer of area. It indicates the pressure of population on land.
Step 2: Compare the states.
- (A) Bihar: Has the highest population density in India, more than 1100 persons per sq. km (Census 2011 data).
- (B) Punjab: Fertile but less densely populated compared to Bihar.
- (C) West Bengal: Very high density, around 1028 persons per sq. km, but still less than Bihar.
- (D) Kerala: High density and high literacy, but lower than Bihar.
Step 3: Conclusion.
Among the options, Bihar has the highest population density.
\[
\boxed{\text{Bihar}}
\]
Study the following graph carefully and answer the following questions