Answer:
Many (h)istorians agree that a major factor contributing to the (G)ermans' defeat in the Battle of the Bulge was their lack of (f)uel.
Explanation:
Capital letters are mainly used for proper nouns, at the start of sentences, dialogues, titles, etc. So, when such a pattern is not used and capital letters are inserted wherever and whenever, that makes a sentence incorrect.
In the given sentence, there are three capital letter errors. First is the "H" in "Historians", "g" in "germans'", "F" in "fuel".
The correct sentence will be-
<u><em>Many historians agree that a major factor contributing to the Germans' defeat in the Battle of the Bulge was their lack of fuel.</em></u>