Answer:
D. Preaching in German and translating the Bible so people could read
Step-by-step explanation:
Martin Luther tought that it individual faith was very important, and that people should seek a persona connection with God, instead of relying on the preachings of the local priest.
The problem was that very few German people could read at the time, let alone read Latin, the language in which the Bible was written.
This is why Luther completed the Task of translating the Bible to German, so that more people could read the Bible by themselves, and develop their individual faith.