If it is not reasonably practicable to eliminate the risk referred to in subclause (1), the PCBU must minimise the risk by providing and maintaining a safe system of work that includes—
(a)
measures for preventing an object from falling freely, so far as is reasonably practicable; or
(b)
if it is not reasonably practicable to prevent the object from falling freely, a system to arrest the fall; or
(c)
if it is not reasonably practicable to comply with paragraph (a) or (b), providing an exclusion zone that persons are prohibited from entering.