Answer:
We were at a disadvantage <em><u>in</u></em><em> </em>that that we weren't too familiar with the language the others were using.
Explanation:
In the given sentence, the correct preposition to be used is "in". This is because "in" will introduce the argument or provide an explanation for the statement before the blank.
With the use of "in", the statement <em>"we weren't too familiar with the language the others were using"</em> provides an explanation for the first statement <em>"[W]e were at a disadvantage"</em>. Whereas the use of the prepositions "by", "with", and "for" are incorrect.
Thus, the correct answer is "in".
I believe C would be the right option for this question
The second statement is the most accurate.
Hope this helps!