Abu'l Hasan al Hujwiri was buried in Lahore, and his tomb-shrine late…

The correct answer is Option (3) → The grandson of Sultan Mahmud of Ghazni constructs a tomb over his grave.

Option (1) Muhammad bin Tughlaq becomes the first Sultan to visit his grave. — Incorrect. Muhammad bin Tughlaq was the first Sultan to visit the shrine of Khwaja Muinuddin at Ajmer. That visit belongs to the story of a different shrine.

Option (2) Sultan Mahmud of Ghazni himself constructs a tomb over his grave. — Incorrect. Hujwiri came to India in 1039 as a captive of the Turkish army. The tomb over his grave was built by Mahmud's grandson.

Option (3) The grandson of Sultan Mahmud of Ghazni constructs a tomb over his grave. — Correct. After Hujwiri died in 1073, the grandson of Sultan Mahmud of Ghazni built a tomb over his grave. This tomb-shrine then drew devotees, so a grave became a shrine.

Option (4) Sultan Ghiyasuddin Khalji of Malwa funds a building to house his tomb. — Incorrect. Ghiyasuddin Khalji of Malwa funded the earliest building over Khwaja Muinuddin's tomb at Ajmer, in the late fifteenth century.