To find the missing denominator in the addition sentence \( 1528 + 9 \), we first perform the addition:
\[ 1528 + 9 = 1537 \]
Now, if you are looking for a fraction that results from adding these two numbers, it is not clear from the context what denominator you are looking for. However, considering standard form, you can express 1537 as a fraction over a denominator.
If you wanted to put 1537 over a specific denominator, you could argue that any denominator would work, but you would typically express it using the same number:
For example:
- \( \frac{1537}{1} \) (Here, the denominator is 1).
- If we're looking for a common denominator from the choices given, none directly applies to the addition of whole numbers but if you just want a number among the options, you might represent the number as \( \frac{9}{1} \) for 9.
Since you have provided specific options that seem unrelated to the sum directly but rather a chosen denominator for another expression, without further context, it’s challenging to advise accurately.
However, if we were compelled to choose, we might opt for ‘9’ since it is part of the addition and could represent a form of fractions involving 9 on one side being compared to units of other values.
So, the most fitting option in terms of the context provided would be:
9
Please clarify if there’s more context to your question or if it pertains to a different mathematical concept!