Answer and Explanation:
I believe the mistake in the original sentence is caused by a dangling modifier. Let's take a look at it:
Preparing our dinner, the smell of the chicken made Ben hungry.
The underlined portion is the modifier. Notice the sentence sounds strange, even ambiguous. Usually, the modifier comes close to the noun it intends to modify. But, in this case, the closest noun is "smell". There is no way for the smell to be "preparing our dinner". That is what makes the sentence sound so strange.
To correct it, we need to change the modifier a bit in order to clarify to whom it refers. It could be "me", the speaker, or it could very well be Ben the one cooking dinner. Take a look at the options and see how much clearer they sound:
- While I was preparing our dinner, the smell of the chicken made Ben hungry.
- While Ben was preparing our dinner, the smell of the chicken made him hungry.