The correct answer is option 3, Gobind Singh. Gobind Singh introduced the Sikh military sect called the Khalsa in 1699. The Khalsa was created as a response to the persecution faced by Sikhs at the time and served as a way to protect the Sikh community. Gobind Singh initiated the first group of Khalsa members by performing a special ceremony known as Amrit Sanchar. During this ceremony, they were given the title of Singh (lion) and were required to adhere to a strict code of conduct, including wearing the Five Ks (special symbols of Sikh identity). The Khalsa played a significant role in defending Sikhism and promoting its values, and it continues to be an important institution in Sikhism today.