Answer:
B. They should retest the current model, as there may have been an error in the testing methods the first time.
Step-by-step explanation:
If in the studies carried out theoretically it is verified that the model works, that means that at the time of testing to confirm the veracity of the investigation there was an error and that is why it does not work in real cases. therefore a feedback should be made to identify where the faults are and correct.