The correct answer is A. 3 years.
The Block Development Council (BDC) is a local self-government institution in India at the block level. It is constituted under the Panchayati Raj Act, 1993. The BDC is headed by a Chairperson, who is elected by the elected members of the BDC. The term of office of the Chairperson is 3 years.
The BDC is responsible for the development of the block area. It undertakes various developmental activities, such as construction of roads, schools, and hospitals. It also provides various services, such as water supply, sanitation, and electricity.
The BDC is an important institution of local self-government in India. It plays a vital role in the development of the rural areas.
Option B is incorrect because the term of office of the Chairperson of the Block Development Council is 3 years, not 4 years.
Option C is incorrect because the term of office of the Chairperson of the Block Development Council is 3 years, not 5 years.
Option D is incorrect because the term of office of the Chairperson of the Block Development Council is 3 years, not 6 years.