Option 1 (a and c): This option suggests that Sultan is correctly matched with the Sack of Mahmud Somnath, and Alauddin is correctly matched with the Revolt in Khilji Bengal. However, this is incorrect because Sultan is actually associated with the Conquest of Ghori.

Option 2 (b only): This option suggests that Mohammad is correctly matched with the Conquest of Ghori. This is correct because Sultan Mohammad of Ghori was responsible for the conquest of several regions, including parts of India.

Option 3 (a only): This option suggests that Sultan is correctly matched with the Sack of Mahmud Somnath. This is incorrect because Sultan is actually associated with the Conquest of Ghori.

Option 4 (b and d): This option suggests that Mohammad is correctly matched with the Conquest of Ghori and Bin Tughlaq is correctly matched with Khan`s invasion. However, this is incorrect because Mohammad is associated with the Conquest of Ghori, but Bin Tughlaq is not associated with Khan`s invasion.

Therefore, the correct answer is Option 3, which states that only b (Mohammad and the Conquest of Ghori) is correctly matched.