Article 16 5

(a)

the data subject already has the information;

(b)

the provision of such information proves impossible or would involve a disproportionate effort, in particular for processing for archiving purposes in the public interest, scientific or historical research purposes or statistical purposes or in so far as the obligation referred to in paragraph 1 of this Article is likely to render impossible or seriously impair the achievement of the objectives of that processing;

(c)

obtaining or disclosure is expressly laid down by Union law, which provides appropriate measures to protect the data subject’s legitimate interests; or

(d)

where the personal data must remain confidential subject to an obligation of professional secrecy regulated by Union law, including a statutory obligation of secrecy.