The major religion in Bihar is:

Hinduism
Islam
Sikhism
Buddhism

The correct answer is: a) Hinduism.

Hinduism is the majority religion in Bihar, with around 82.7% of the population identifying as Hindu. Islam is the second largest religion, with around 16.9% of the population identifying as Muslim. Other religions practiced in Bihar include Christianity, Sikhism, and Buddhism.

Hinduism is a religion and dharma that originated in India. It is the world’s oldest major religion, and its followers are called Hindus. Hinduism is a polytheistic religion, meaning that it has many gods and goddesses. The most important Hindu gods are Brahma, Vishnu, and Shiva.

Islam is a monotheistic religion that teaches that there is only one God, Allah. Muslims believe that Muhammad is the prophet of Allah. The holy book of Islam is the Quran.

Sikhism is a monotheistic religion that teaches that there is only one God, Waheguru. Sikhs believe that there is no caste system, and that all people are equal. The holy book of Sikhism is the Guru Granth Sahib.

Buddhism is a religion that teaches that the way to end suffering is to follow the Eightfold Path. The Eightfold Path includes right understanding, right thought, right speech, right action, right livelihood, right effort, right mindfulness, and right concentration.

Bihar is a state in eastern India. It is the third most populous state in India, with a population of over 100 million people. The capital of Bihar is Patna.