answer with explanation:
when dealing with heavy loads, one needs to take certain precautions in order to avoid or prevent from injuries.
for instance, one should avoid lifting above the shoulder level which can end up pulling your muscle.
also, you can either break the load in parts if possible or get some for lifting heavy bulks.
moreover, one should try to lift with the legs while keeping the back straight and not twisting it.
d is the answer
on/off components of a pid controlled accumulates the error over time and responds to system error after the error has been accumulated.
primary groups shape your individual development