The correct answer is option 'B' - District inspector of school.

Explanation:
The highest officer of the education department in the district is the District Inspector of Schools. Below, we will discuss the roles and responsibilities of the District Inspector of Schools and why they hold such an important position in the education department.

Roles and Responsibilities of the District Inspector of Schools:
1. Supervision and Monitoring: The District Inspector of Schools is responsible for supervising and monitoring all the schools within their district. They ensure that the schools are functioning efficiently and effectively, following the prescribed curriculum and maintaining the required standards of education.

2. Quality Control: The District Inspector of Schools plays a crucial role in maintaining the quality of education in the district. They conduct regular inspections of schools to assess the quality of teaching, infrastructure, and other facilities provided to the students. They also evaluate the performance of teachers and take necessary steps to improve the overall quality of education.

3. Implementation of Policies: The District Inspector of Schools is responsible for implementing various educational policies and programs introduced by the government. They ensure that these policies are effectively implemented in all the schools within their district. They also provide guidance and support to the school authorities in implementing these policies.

4. Teacher Training and Development: The District Inspector of Schools is involved in the training and development of teachers. They organize workshops, seminars, and training programs for teachers to enhance their skills and knowledge. They also provide guidance to the teachers on effective teaching methodologies and help them in improving their teaching abilities.

5. Student Welfare: The District Inspector of Schools is responsible for the overall welfare of the students in the district. They address any issues or grievances raised by the students or their parents and take appropriate action to resolve them. They also work towards creating a safe and conducive learning environment for the students.

Importance of the District Inspector of Schools:
1. Ensuring Accountability: The District Inspector of Schools ensures that all schools within the district are accountable for providing quality education. They monitor the performance of schools and take necessary actions to address any shortcomings or irregularities.

2. Maintaining Standards: The District Inspector of Schools plays a crucial role in maintaining the standards of education in the district. They ensure that all schools follow the prescribed curriculum and adhere to the guidelines set by the education department.

3. Facilitating Improvement: The District Inspector of Schools identifies areas of improvement in schools and provides necessary guidance and support to help them enhance their performance. They help schools in implementing best practices and innovative teaching methods.

In conclusion, the District Inspector of Schools is the highest officer of the education department in the district. They have important roles and responsibilities in supervising and monitoring schools, maintaining quality standards, implementing policies, training and developing teachers, and ensuring student welfare. Their position is crucial in ensuring accountability, maintaining standards, and facilitating improvement in the education system within the district.