Question

three of the following were ideas taught by martin luther which was not
every Christian can interpret the bible
faith alone can save a persons soul
the clergy is not necessary for worship
the pope is supreme in religious affairs

Answer 1

Martin Luther taught the Christ was the head of the church.  He did not give much weight to the authority of the pope.

Answer 2

D. The Pope is supreme in religious affairs.

Such is why the Church heavily criticized Martin Luther and led to the Reformation and Counter-Reformation.