The system of alternating power between the DMK and AIADMK has characterized Tamil Nadu politics since:

1960s
1970s
1980s
1990s

The correct answer is: a) 1960s

The Dravida Munnetra Kazhagam (DMK) and All India Anna Dravida Munnetra Kazhagam (AIADMK) are two major political parties in the Indian state of Tamil Nadu. They have been alternating power in the state since the 1960s.

The DMK was founded in 1949 by C. N. Annadurai. It is a social democratic party that advocates for the rights of the Tamil people. The AIADMK was founded in 1972 by M. G. Ramachandran. It is a centrist party that is known for its populist policies.

The DMK and AIADMK have a long history of rivalry. They have often been accused of using violence and intimidation against each other. However, they have also been able to work together on some issues, such as the development of Tamil Nadu.

The system of alternating power between the DMK and AIADMK has been criticized for being unstable and for not leading to any real progress in the state. However, it has also been praised for providing the people of Tamil Nadu with a choice of parties and for preventing any one party from becoming too powerful.

The DMK and AIADMK are likely to continue to dominate Tamil Nadu politics for the foreseeable future. It remains to be seen whether they will be able to put aside their differences and work together to improve the lives of the people of the state.

Option b) is incorrect because the DMK and AIADMK were not founded until the 1940s and 1970s, respectively.

Option c) is incorrect because the DMK and AIADMK did not start alternating power until the 1960s.

Option d) is incorrect because the DMK and AIADMK did not start alternating power until the 1960s.