Answer:
The correct answer is - they are both systems that are performing similar functions.
Step-by-step explanation:
In the given question there are two different entities that do a similar kind of work or perform similar functions, however, the systems are different as one system involves the manpower of a worker whereas the other system involves the high power of a bulldozer.
The work is similar but the amount of the work varies as manual work done by a worker is less in comparison to the bulldozer.