The above sentence has clearly described that the patient data conrfimed already about his diagnosis of illness. Therefore, past tense is essential to correct the sentence, in which “confirms” should be replaced with “confirmed”.
Therefore, the correct sentence is “The data confirmed that the patient is suffering from extreme anxiety”. This sentence was connected with “And” with other sentence, which is a grammatically correct.
Thus, the options (c), (d) and (a) are incorrect.
The above sentence has clearly described that the patient data confirmed already about his diagnosis of illness. Therefore, past tense is essential to correct the sentence, in which “confirms” should be replaced with “confirmed”.
Therefore, the correct option is – b. confirms.