Answer:
d. 9!
To solve this problem, you can use the permutation formula, which is given by the following:
In this formula,
is the total number of items, and
is the number of items being chosen at a time.
In this case, we have a total of 9 letters in the word WISCONSIN, and we want to rearrange them to form 9-letter strings. Therefore, we can use the permutation formula as follows:
This means that there are 362,880 different 9-letter strings that can be made by rearranging the characters in the word WISCONSIN.