The correct answer is (b) Bihar.
The literacy rate in Bihar was 63.82% in 2011, the lowest among all the states in India. The literacy rate in Odisha was 72.87%, the literacy rate in Jharkhand was 67.61%, and the literacy rate in Chhattisgarh was 70.26%.
The low literacy rate in Bihar is due to a number of factors, including poverty, lack of access to education, and gender inequality. The state has a high proportion of people living below the poverty line, and many families cannot afford to send their children to school. There is also a shortage of schools and teachers in rural areas, making it difficult for children to access education. In addition, girls are often discouraged from going to school, and many are married off at a young age.
The government of Bihar has taken a number of steps to improve the literacy rate in the state, including building more schools, providing scholarships to students, and launching awareness campaigns. However, more needs to be done to ensure that all children in Bihar have access to quality education.