Explanation:

The Khalsa Panth is the collective body of initiated Sikhs, established by Guru Gobind Singh, the tenth Sikh Guru, as a spiritual and martial brotherhood. * **Correct Option (B) 1699:** The Khalsa Panth was formally founded by Guru Gobind Singh on Baisakhi day in the year **1699** at Anandpur Sahib. This momentous event involved the initiation of the Panj Pyare (the Five Beloved Ones) and the establishment of a distinct code of conduct and identity for Sikhs, transforming the community into a disciplined and dedicated force committed to righteousness and justice. It marked a pivotal moment in Sikh history, giving Sikhs a unique identity and purpose. * **Incorrect Option (A) 1599:** The year 1599 predates the birth of Guru Gobind Singh (1666) and therefore cannot be the year of the Khalsa's founding. This option is historically inaccurate. * **Incorrect Option (C) 1707:** The year 1707 is significant as the year of Guru Gobind Singh's passing, but it is not the year the Khalsa was founded. He passed away in Nanded, Maharashtra, in this year. * **Incorrect Option (D) 1657:** The year 1657 is not associated with any major event in the founding of the Khalsa Panth. Guru Gobind Singh was born nine years later.