The following principles apply in determining whether a public or other authority has a duty of care or has breached a duty of care in proceedings for civil liability to which this Part applies--
(a) the functions required to be exercised by the authority are limited by the financial and other resources that are reasonably available to the authority for the purpose of exercising those functions,
(b) the general allocation of those resources by the authority is not open to challenge,
(c) the functions required to be exercised by the authority are to be determined by reference to the broad range of its activities (and not merely by reference to the matter to which the proceedings relate),
(d) the authority may rely on evidence of its compliance with the general procedures and applicable standards for the exercise of its functions as evidence of the proper exercise of its functions in the matter to which the proceedings relate.