The correct option is
A Their mystical doctrine of union with God through love was regarded as heretical and attacked by orthodox Islam.
Examples of people presumably executed for their Sufi views and practices include Abbasid mystic Mansur Al-Hallaj in 922, Ayn al-Quzat Hamadani in 1131, Iraqi philosopher Shahab al-Din Suhrawardi in 1191, Ottoman mystic and mutineer Sheikh Bedreddin in 1420 and wandering dervish Sarmad Kashani in 1661 in Mughal India. The exact reasons for executions in some of those cases were disputed.
Suppression of Sufism in the Islamic world has a long history and it has been motivated by both religious purposes and in later centuries, also political purposes. Though some Muslims see Sufism as a pious and pure expression of faith, its doctrines and practices have been rejected by others. Sufism was seen as emotional and uncontrollable, reaching beyond reason to a state of ecstasy and Truth reached through practices of dancing and physical self-deprivation. It is regarded as a dissenting form of worship at odds with authoritarian power structures. This was in conflict with the trends of the 19th century and focus on the nation-state, which continued through the end of World War I. The drive for modernization that characterized this era favored a "rational" style of religion. The suppression of Sufism during this period was guided by political consideration rather than the objections of Islamic orthodoxy. Sufi leaders were influential and thus posed a threat, at least potentially, to the existence of the fledgling nation-states in the aftermath of the war. Hence, Option A is correct. The Sufis were peaceful and their preaching of worldly detachment attracted many of the common people. Hence, the rest of the options are incorrect.