All but one of the following triggered the Mahdiyya Movement in Sudan

A.

The foreign government's growing reliance on European Christians

B.

The Sudanese of governmental efforts to suppress the lucrative slave trade

C.

Unpleasant immigration policy of the foreign government

D.

Heavy taxation

Correct answer is C

Unpleasant immigration policy of the foreign government is the correct answer. For reasons of heavy taxation which led to famine, depopulation etc, the foreign government's increased reliance on European Christians including its fight against slave trade, among related other reasons, led tp the Madhiyya revolution.