(a) That's wrong. For liability in Negligence to arise, it must have been reasonably foreseeable to a person in the defendant's position that injury or harm of some kind would happen to someone as a result of the kind of conduct engaged in by the defendant.

This is not a particularly difficult test to satisfy. It need not be foreseeable exactly what type of harm will be caused, nor exactly how it will occur. Nor need it be foreseeable exactly who might be injured. It is sufficient if the plaintiff is a person, or a member of the class of persons, who might foreseeably suffer harm as a result of the defendant's conduct.

It will be obvious, in many circumstances, to a person in the defendant's position that the conduct in question is likely to cause harm of some kind to some person or persons - driving too fast on a busy road; selling contaminated food; or failing to safeguard dangerous equipment are all clear examples.

In the present case, A has left potentially dangerous equipment unattended in his driveway. It is clearly foreseeable that someone might suffer some kind of harm as a result. It does not matter that the particular person, and the particular harm, are not foreseeable.