What was the term used by the disciples of Nizamuddin Auliya to address him?

Sultan-ul-mashaikh

The correct answer is Option 1- Sultan-ul-mashaikh

Occasionally the sufi shaikh was addressed with high-sounding titles. For example, the disciples of Nizamuddin Auliya addressed him as sultan-ul-mashaikh (literally, Sultan amongst shaikhs).

Amir Khusrau was a disciple of Shaikh Nizamuddin Auliya. Nizamuddin Auliya was a 14th-century Sufi saint and poet. His dargah (tomb) is located in Delhi, and it is a significant Sufi shrine in the country.