5The processing is necessary—
(a)for the administration of justice,
(b)for the exercise of any functions of either House of Parliament,
(c)for the exercise of any functions conferred on a person by an enactment or rule of law,
(d)for the exercise of any functions of the Crown, a Minister of the Crown or a government department, or
(e)for the exercise of any other functions of a public nature exercised in the public interest by a person.