The correct answer is (a) Nizamuddin Aulia.
Nizamuddin Aulia was a Sufi saint who lived in Delhi from 1238 to 1325. He was the most reputed disciple of Shaikh Farid and had seen the reign of as many as seven sultans of Delhi. He was a popular figure and attracted many followers from all walks of life. He was known for his piety and his teachings on love and compassion.
Shaikh Nasiruddin Chirag was a Sufi saint who lived in Delhi from 1275 to 1356. He was a disciple of Nizamuddin Aulia and was known for his scholarship and his piety. He was the founder of the Chishti order of Sufis.
Shaikh Salim Chisti was a Sufi saint who lived in Fatehpur Sikri from 1478 to 1572. He was a disciple of Moinuddin Chishti and was known for his miracles and his teachings on love and devotion. He was the spiritual guide of Akbar the Great.
(d) None of the above is not the correct answer because Nizamuddin Aulia was the most reputed disciple of Shaikh Farid who had seen the reign of as many as seven sultans of Delhi.