Answer: A) Testing helps schools identify teaching techniques that work.
Step-by-step explanation: a thesis is an idea or theory that is expressed as a statement and is discussed in a logical way in order to be proved or refuted. In the given sentence we can see the thesis that standardized tests are an important educational tool, from the given options, the only one that states a reason that support this thesis is option A, because it says that test can be helpful to identify teaching techniques that work, the other options are arguments against the thesis.