Fill in the blank with the correct preposition.
There is no exception __________ this algorithm.

to

The correct preposition to fill in the blank is to. The preposition to is used to indicate direction or purpose. In this case, there is no exception to this algorithm, which means that the algorithm applies to all cases.

The other options are incorrect.

• For is used to indicate purpose or destination.
• At is used to indicate a specific point or place.
• About is used to indicate something that is being discussed or talked about.