Option 1 is the correct answer as all three statements are correct.

Statement I states that Dayanand Saraswati founded the Arya Samaj in 1875, which is true. Dayanand Saraswati, an Indian philosopher and social reformer, established the Arya Samaj as a Hindu reform movement that aimed to purify Hinduism from corruptions and superstitions.

Statement II states that the Arya Samaj repudiated the authority of the caste system, which is also true. The Arya Samaj emphasized equality among all individuals regardless of their caste or social status. They believed in the unity of all Hindus and rejected the discriminatory practices associated with the caste system.

Statement III states that Dayanand Saraswati was born in a Brahman family, which is true as well. Dayanand Saraswati was born into a Brahman family in Gujarat, India.

So, option 1 is the correct answer as all three statements are correct and provide accurate information about Dayanand Saraswati and the Arya Samaj.