When teachers choose questions to ask, reflect on the level of understanding that student answers demonstrate, and then decide how to adjust instruction to improve results, they are making what kinds of decisions?

The answer is: Evaluating

The evaluation process in decision making is being done in order to know whether the system that already implemented actually fulfilling the standard. (in the sample above, it's being done by reflecting on the level of understanding that student answers).

After the result come up, the teachers would know whether the previous system is successful or not. If the result is not up to standard, then they could formulate new approaches that can be used to improve.