Secularism refers to the principle or belief that the state should not favor or promote any particular religion. It is based on the idea of separating religious institutions and religious matters from the affairs of the state. In a secular state, the government remains neutral in matters of religion and treats all religions equally, without showing any preference or discrimination.

Several reasons contribute to the establishment of secularism in a society. It ensures that people of different religious beliefs can coexist peacefully and have equal rights and opportunities. It also prevents any particular religion from dominating the state and imposing its beliefs on the entire population. Moreover, secularism promotes freedom of religion, allowing individuals to practice their faith without fear of persecution or prejudice.

To understand why option 'C' is the correct answer, let's break down the other options:

a) State is against to all religious: This option suggests that the state is actively opposed to all religions. However, secularism does not promote hostility towards religions but rather neutrality.

b) State accepts only one religion: This option implies that the state gives preference to a specific religion, which goes against the principles of secularism. A secular state treats all religions equally and does not favor any particular one.

c) State will not give any special concern with any religion: This option accurately represents the essence of secularism. A secular state does not show any special concern or preference towards any religion. It ensures equal treatment of all religious communities.

d) None of these: This option is incorrect as option 'C' accurately describes secularism.

In conclusion, secularism advocates for a state that remains neutral in religious matters, treats all religions equally, and does not favor or discriminate against any particular religion. It promotes harmony, freedom of religion, and equal rights for individuals of different faiths.