The correct answer is option 4. The statement "The Delhi conference of the Central Khilafat Committee in 1920 decided to launch a massive Non-Cooperation Movement" is not correct.

To understand why this statement is incorrect, let`s review the other options:

Option 1: The Khilafat Movement did indeed demand that the Khalifa (the leader of the Muslim world) retain control over Muslim holy places. This was in response to concerns about the weakening of the Ottoman Empire and the potential loss of control over these important religious sites.

Option 2: The radical trend in the Khilafat Movement was indeed represented by younger leaders like Muhammad Ali, Shaukat Ali, and Maulana Azad. These leaders advocated for more aggressive action to protect the Khalifa and Muslim interests.

Option 3: Indian Muslim leaders did use the Khilafat movement as a symbol to unite the Indian Muslim community. They felt a sense of solidarity with fellow Muslims in the Ottoman Empire and saw the Khilafat cause as an opportunity to unite Muslims in India against British colonial rule.

From these explanations, we can conclude that the correct answer should be option 4.