Assume that there is a trained deep neural network model for identifying cats and dogs, and now this model will be used to detect the locations of cats in a new dataset. Which of the following statement true?

A$.$ Adjust the last several layers of the network and change the last layer to the regression layer.

B$.$ Retrain the existing model using a new dataset.

C$.$ None of the above

D$.$ Remove the last layer of the network and retrain the existing model.